1 /* 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95 39 * $FreeBSD$ 40 */ 41 42 /* 43 * External virtual filesystem routines 44 */ 45 #include "opt_ddb.h" 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/bio.h> 50 #include <sys/buf.h> 51 #include <sys/conf.h> 52 #include <sys/eventhandler.h> 53 #include <sys/fcntl.h> 54 #include <sys/kernel.h> 55 #include <sys/kthread.h> 56 #include <sys/malloc.h> 57 #include <sys/mount.h> 58 #include <sys/namei.h> 59 #include <sys/stat.h> 60 #include <sys/sysctl.h> 61 #include <sys/syslog.h> 62 #include <sys/vmmeter.h> 63 #include <sys/vnode.h> 64 65 #include <vm/vm.h> 66 #include <vm/vm_object.h> 67 #include <vm/vm_extern.h> 68 #include <vm/pmap.h> 69 #include <vm/vm_map.h> 70 #include <vm/vm_page.h> 71 #include <vm/uma.h> 72 73 static MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure"); 74 75 static void addalias(struct vnode *vp, dev_t nvp_rdev); 76 static void insmntque(struct vnode *vp, struct mount *mp); 77 static void vclean(struct vnode *vp, int flags, struct thread *td); 78 static void vlruvp(struct vnode *vp); 79 80 /* 81 * Number of vnodes in existence. Increased whenever getnewvnode() 82 * allocates a new vnode, never decreased. 83 */ 84 static unsigned long numvnodes; 85 86 SYSCTL_LONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, ""); 87 88 /* 89 * Conversion tables for conversion from vnode types to inode formats 90 * and back. 91 */ 92 enum vtype iftovt_tab[16] = { 93 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 94 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD, 95 }; 96 int vttoif_tab[9] = { 97 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 98 S_IFSOCK, S_IFIFO, S_IFMT, 99 }; 100 101 /* 102 * List of vnodes that are ready for recycling. 103 */ 104 static TAILQ_HEAD(freelst, vnode) vnode_free_list; 105 106 /* 107 * Minimum number of free vnodes. If there are fewer than this free vnodes, 108 * getnewvnode() will return a newly allocated vnode. 109 */ 110 static u_long wantfreevnodes = 25; 111 SYSCTL_LONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, ""); 112 /* Number of vnodes in the free list. */ 113 static u_long freevnodes; 114 SYSCTL_LONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, ""); 115 116 /* 117 * Various variables used for debugging the new implementation of 118 * reassignbuf(). 119 * XXX these are probably of (very) limited utility now. 120 */ 121 static int reassignbufcalls; 122 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, ""); 123 static int nameileafonly; 124 SYSCTL_INT(_vfs, OID_AUTO, nameileafonly, CTLFLAG_RW, &nameileafonly, 0, ""); 125 126 #ifdef ENABLE_VFS_IOOPT 127 /* See NOTES for a description of this setting. */ 128 int vfs_ioopt; 129 SYSCTL_INT(_vfs, OID_AUTO, ioopt, CTLFLAG_RW, &vfs_ioopt, 0, ""); 130 #endif 131 132 /* 133 * Cache for the mount type id assigned to NFS. This is used for 134 * special checks in nfs/nfs_nqlease.c and vm/vnode_pager.c. 135 */ 136 int nfs_mount_type = -1; 137 138 /* To keep more than one thread at a time from running vfs_getnewfsid */ 139 static struct mtx mntid_mtx; 140 141 /* For any iteration/modification of vnode_free_list */ 142 static struct mtx vnode_free_list_mtx; 143 144 /* 145 * For any iteration/modification of dev->si_hlist (linked through 146 * v_specnext) 147 */ 148 static struct mtx spechash_mtx; 149 150 /* Publicly exported FS */ 151 struct nfs_public nfs_pub; 152 153 /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ 154 static uma_zone_t vnode_zone; 155 static uma_zone_t vnodepoll_zone; 156 157 /* Set to 1 to print out reclaim of active vnodes */ 158 int prtactive; 159 160 /* 161 * The workitem queue. 162 * 163 * It is useful to delay writes of file data and filesystem metadata 164 * for tens of seconds so that quickly created and deleted files need 165 * not waste disk bandwidth being created and removed. To realize this, 166 * we append vnodes to a "workitem" queue. When running with a soft 167 * updates implementation, most pending metadata dependencies should 168 * not wait for more than a few seconds. Thus, mounted on block devices 169 * are delayed only about a half the time that file data is delayed. 170 * Similarly, directory updates are more critical, so are only delayed 171 * about a third the time that file data is delayed. Thus, there are 172 * SYNCER_MAXDELAY queues that are processed round-robin at a rate of 173 * one each second (driven off the filesystem syncer process). The 174 * syncer_delayno variable indicates the next queue that is to be processed. 175 * Items that need to be processed soon are placed in this queue: 176 * 177 * syncer_workitem_pending[syncer_delayno] 178 * 179 * A delay of fifteen seconds is done by placing the request fifteen 180 * entries later in the queue: 181 * 182 * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] 183 * 184 */ 185 static int syncer_delayno; 186 static long syncer_mask; 187 LIST_HEAD(synclist, vnode); 188 static struct synclist *syncer_workitem_pending; 189 190 #define SYNCER_MAXDELAY 32 191 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ 192 static int syncdelay = 30; /* max time to delay syncing data */ 193 static int filedelay = 30; /* time to delay syncing files */ 194 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, ""); 195 static int dirdelay = 29; /* time to delay syncing directories */ 196 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, ""); 197 static int metadelay = 28; /* time to delay syncing metadata */ 198 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, ""); 199 static int rushjob; /* number of slots to run ASAP */ 200 static int stat_rush_requests; /* number of times I/O speeded up */ 201 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, ""); 202 203 /* 204 * Number of vnodes we want to exist at any one time. This is mostly used 205 * to size hash tables in vnode-related code. It is normally not used in 206 * getnewvnode(), as wantfreevnodes is normally nonzero.) 207 * 208 * XXX desiredvnodes is historical cruft and should not exist. 209 */ 210 int desiredvnodes; 211 SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW, 212 &desiredvnodes, 0, "Maximum number of vnodes"); 213 static int minvnodes; 214 SYSCTL_INT(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, 215 &minvnodes, 0, "Minimum number of vnodes"); 216 static int vnlru_nowhere; 217 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, &vnlru_nowhere, 0, 218 "Number of times the vnlru process ran without success"); 219 220 /* Hook for calling soft updates */ 221 int (*softdep_process_worklist_hook)(struct mount *); 222 223 #ifdef DEBUG_VFS_LOCKS 224 /* Print lock violations */ 225 int vfs_badlock_print = 1; 226 /* Panic on violation */ 227 int vfs_badlock_panic = 1; 228 229 void 230 vop_rename_pre(void *ap) 231 { 232 struct vop_rename_args *a = ap; 233 234 /* Check the source (from) */ 235 if (a->a_tdvp != a->a_fdvp) 236 ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked.\n"); 237 if (a->a_tvp != a->a_fvp) 238 ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: tvp locked.\n"); 239 240 /* Check the target */ 241 if (a->a_tvp) 242 ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked.\n"); 243 244 ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked.\n"); 245 } 246 247 void 248 vop_strategy_pre(void *ap) 249 { 250 struct vop_strategy_args *a = ap; 251 struct buf *bp; 252 253 bp = a->a_bp; 254 255 /* 256 * Cluster ops lock their component buffers but not the IO container. 257 */ 258 if ((bp->b_flags & B_CLUSTER) != 0) 259 return; 260 261 if (BUF_REFCNT(bp) < 1) { 262 if (vfs_badlock_print) 263 printf("VOP_STRATEGY: bp is not locked but should be.\n"); 264 if (vfs_badlock_panic) 265 Debugger("Lock violation.\n"); 266 } 267 } 268 269 void 270 vop_lookup_pre(void *ap) 271 { 272 struct vop_lookup_args *a = ap; 273 struct vnode *dvp; 274 275 dvp = a->a_dvp; 276 277 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP"); 278 } 279 280 void 281 vop_lookup_post(void *ap, int rc) 282 { 283 struct vop_lookup_args *a = ap; 284 struct componentname *cnp; 285 struct vnode *dvp; 286 struct vnode *vp; 287 int flags; 288 289 dvp = a->a_dvp; 290 cnp = a->a_cnp; 291 vp = *(a->a_vpp); 292 flags = cnp->cn_flags; 293 294 295 /* 296 * If this is the last path component for this lookup and LOCPARENT 297 * is set, OR if there is an error the directory has to be locked. 298 */ 299 if ((flags & LOCKPARENT) && (flags & ISLASTCN)) 300 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP (LOCKPARENT)"); 301 else if (rc != 0) 302 ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP (error)"); 303 else if (dvp != vp) 304 ASSERT_VOP_UNLOCKED(dvp, "VOP_LOOKUP (dvp)"); 305 306 if (flags & PDIRUNLOCK) 307 ASSERT_VOP_UNLOCKED(dvp, "VOP_LOOKUP (PDIRUNLOCK)"); 308 309 if (rc == 0) 310 ASSERT_VOP_LOCKED(vp, "VOP_LOOKUP (vpp)"); 311 } 312 313 #endif /* DEBUG_VFS_LOCKS */ 314 315 void 316 v_addpollinfo(struct vnode *vp) 317 { 318 vp->v_pollinfo = uma_zalloc(vnodepoll_zone, M_WAITOK); 319 mtx_init(&vp->v_pollinfo->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); 320 } 321 322 /* 323 * Initialize the vnode management data structures. 324 */ 325 static void 326 vntblinit(void *dummy __unused) 327 { 328 329 desiredvnodes = maxproc + cnt.v_page_count / 4; 330 minvnodes = desiredvnodes / 4; 331 mtx_init(&mountlist_mtx, "mountlist", NULL, MTX_DEF); 332 mtx_init(&mntvnode_mtx, "mntvnode", NULL, MTX_DEF); 333 mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); 334 mtx_init(&spechash_mtx, "spechash", NULL, MTX_DEF); 335 TAILQ_INIT(&vnode_free_list); 336 mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF); 337 vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, 338 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 339 vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), 340 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 341 /* 342 * Initialize the filesystem syncer. 343 */ 344 syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, 345 &syncer_mask); 346 syncer_maxdelay = syncer_mask + 1; 347 } 348 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL) 349 350 351 /* 352 * Mark a mount point as busy. Used to synchronize access and to delay 353 * unmounting. Interlock is not released on failure. 354 */ 355 int 356 vfs_busy(mp, flags, interlkp, td) 357 struct mount *mp; 358 int flags; 359 struct mtx *interlkp; 360 struct thread *td; 361 { 362 int lkflags; 363 364 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 365 if (flags & LK_NOWAIT) 366 return (ENOENT); 367 mp->mnt_kern_flag |= MNTK_MWAIT; 368 /* 369 * Since all busy locks are shared except the exclusive 370 * lock granted when unmounting, the only place that a 371 * wakeup needs to be done is at the release of the 372 * exclusive lock at the end of dounmount. 373 */ 374 msleep(mp, interlkp, PVFS, "vfs_busy", 0); 375 return (ENOENT); 376 } 377 lkflags = LK_SHARED | LK_NOPAUSE; 378 if (interlkp) 379 lkflags |= LK_INTERLOCK; 380 if (lockmgr(&mp->mnt_lock, lkflags, interlkp, td)) 381 panic("vfs_busy: unexpected lock failure"); 382 return (0); 383 } 384 385 /* 386 * Free a busy filesystem. 387 */ 388 void 389 vfs_unbusy(mp, td) 390 struct mount *mp; 391 struct thread *td; 392 { 393 394 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td); 395 } 396 397 /* 398 * Lookup a mount point by filesystem identifier. 399 */ 400 struct mount * 401 vfs_getvfs(fsid) 402 fsid_t *fsid; 403 { 404 register struct mount *mp; 405 406 mtx_lock(&mountlist_mtx); 407 TAILQ_FOREACH(mp, &mountlist, mnt_list) { 408 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 409 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { 410 mtx_unlock(&mountlist_mtx); 411 return (mp); 412 } 413 } 414 mtx_unlock(&mountlist_mtx); 415 return ((struct mount *) 0); 416 } 417 418 /* 419 * Get a new unique fsid. Try to make its val[0] unique, since this value 420 * will be used to create fake device numbers for stat(). Also try (but 421 * not so hard) make its val[0] unique mod 2^16, since some emulators only 422 * support 16-bit device numbers. We end up with unique val[0]'s for the 423 * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. 424 * 425 * Keep in mind that several mounts may be running in parallel. Starting 426 * the search one past where the previous search terminated is both a 427 * micro-optimization and a defense against returning the same fsid to 428 * different mounts. 429 */ 430 void 431 vfs_getnewfsid(mp) 432 struct mount *mp; 433 { 434 static u_int16_t mntid_base; 435 fsid_t tfsid; 436 int mtype; 437 438 mtx_lock(&mntid_mtx); 439 mtype = mp->mnt_vfc->vfc_typenum; 440 tfsid.val[1] = mtype; 441 mtype = (mtype & 0xFF) << 24; 442 for (;;) { 443 tfsid.val[0] = makeudev(255, 444 mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); 445 mntid_base++; 446 if (vfs_getvfs(&tfsid) == NULL) 447 break; 448 } 449 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 450 mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; 451 mtx_unlock(&mntid_mtx); 452 } 453 454 /* 455 * Knob to control the precision of file timestamps: 456 * 457 * 0 = seconds only; nanoseconds zeroed. 458 * 1 = seconds and nanoseconds, accurate within 1/HZ. 459 * 2 = seconds and nanoseconds, truncated to microseconds. 460 * >=3 = seconds and nanoseconds, maximum precision. 461 */ 462 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; 463 464 static int timestamp_precision = TSP_SEC; 465 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, 466 ×tamp_precision, 0, ""); 467 468 /* 469 * Get a current timestamp. 470 */ 471 void 472 vfs_timestamp(tsp) 473 struct timespec *tsp; 474 { 475 struct timeval tv; 476 477 switch (timestamp_precision) { 478 case TSP_SEC: 479 tsp->tv_sec = time_second; 480 tsp->tv_nsec = 0; 481 break; 482 case TSP_HZ: 483 getnanotime(tsp); 484 break; 485 case TSP_USEC: 486 microtime(&tv); 487 TIMEVAL_TO_TIMESPEC(&tv, tsp); 488 break; 489 case TSP_NSEC: 490 default: 491 nanotime(tsp); 492 break; 493 } 494 } 495 496 /* 497 * Set vnode attributes to VNOVAL 498 */ 499 void 500 vattr_null(vap) 501 register struct vattr *vap; 502 { 503 504 vap->va_type = VNON; 505 vap->va_size = VNOVAL; 506 vap->va_bytes = VNOVAL; 507 vap->va_mode = VNOVAL; 508 vap->va_nlink = VNOVAL; 509 vap->va_uid = VNOVAL; 510 vap->va_gid = VNOVAL; 511 vap->va_fsid = VNOVAL; 512 vap->va_fileid = VNOVAL; 513 vap->va_blocksize = VNOVAL; 514 vap->va_rdev = VNOVAL; 515 vap->va_atime.tv_sec = VNOVAL; 516 vap->va_atime.tv_nsec = VNOVAL; 517 vap->va_mtime.tv_sec = VNOVAL; 518 vap->va_mtime.tv_nsec = VNOVAL; 519 vap->va_ctime.tv_sec = VNOVAL; 520 vap->va_ctime.tv_nsec = VNOVAL; 521 vap->va_flags = VNOVAL; 522 vap->va_gen = VNOVAL; 523 vap->va_vaflags = 0; 524 } 525 526 /* 527 * This routine is called when we have too many vnodes. It attempts 528 * to free <count> vnodes and will potentially free vnodes that still 529 * have VM backing store (VM backing store is typically the cause 530 * of a vnode blowout so we want to do this). Therefore, this operation 531 * is not considered cheap. 532 * 533 * A number of conditions may prevent a vnode from being reclaimed. 534 * the buffer cache may have references on the vnode, a directory 535 * vnode may still have references due to the namei cache representing 536 * underlying files, or the vnode may be in active use. It is not 537 * desireable to reuse such vnodes. These conditions may cause the 538 * number of vnodes to reach some minimum value regardless of what 539 * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. 540 */ 541 static int 542 vlrureclaim(struct mount *mp, int count) 543 { 544 struct vnode *vp; 545 int done; 546 int trigger; 547 int usevnodes; 548 549 /* 550 * Calculate the trigger point, don't allow user 551 * screwups to blow us up. This prevents us from 552 * recycling vnodes with lots of resident pages. We 553 * aren't trying to free memory, we are trying to 554 * free vnodes. 555 */ 556 usevnodes = desiredvnodes; 557 if (usevnodes <= 0) 558 usevnodes = 1; 559 trigger = cnt.v_page_count * 2 / usevnodes; 560 561 done = 0; 562 mtx_lock(&mntvnode_mtx); 563 while (count && (vp = TAILQ_FIRST(&mp->mnt_nvnodelist)) != NULL) { 564 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 565 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 566 567 if (vp->v_type != VNON && 568 vp->v_type != VBAD && 569 VMIGHTFREE(vp) && /* critical path opt */ 570 (vp->v_object == NULL || vp->v_object->resident_page_count < trigger) && 571 mtx_trylock(&vp->v_interlock) 572 ) { 573 mtx_unlock(&mntvnode_mtx); 574 if (VMIGHTFREE(vp)) { 575 vgonel(vp, curthread); 576 done++; 577 } else { 578 mtx_unlock(&vp->v_interlock); 579 } 580 mtx_lock(&mntvnode_mtx); 581 } 582 --count; 583 } 584 mtx_unlock(&mntvnode_mtx); 585 return done; 586 } 587 588 /* 589 * Attempt to recycle vnodes in a context that is always safe to block. 590 * Calling vlrurecycle() from the bowels of filesystem code has some 591 * interesting deadlock problems. 592 */ 593 static struct proc *vnlruproc; 594 static int vnlruproc_sig; 595 596 static void 597 vnlru_proc(void) 598 { 599 struct mount *mp, *nmp; 600 int s; 601 int done; 602 struct proc *p = vnlruproc; 603 struct thread *td = FIRST_THREAD_IN_PROC(p); /* XXXKSE */ 604 605 mtx_lock(&Giant); 606 607 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, p, 608 SHUTDOWN_PRI_FIRST); 609 610 s = splbio(); 611 for (;;) { 612 kthread_suspend_check(p); 613 if (numvnodes - freevnodes <= desiredvnodes * 9 / 10) { 614 vnlruproc_sig = 0; 615 tsleep(vnlruproc, PVFS, "vlruwt", 0); 616 continue; 617 } 618 done = 0; 619 mtx_lock(&mountlist_mtx); 620 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 621 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) { 622 nmp = TAILQ_NEXT(mp, mnt_list); 623 continue; 624 } 625 done += vlrureclaim(mp, 10); 626 mtx_lock(&mountlist_mtx); 627 nmp = TAILQ_NEXT(mp, mnt_list); 628 vfs_unbusy(mp, td); 629 } 630 mtx_unlock(&mountlist_mtx); 631 if (done == 0) { 632 #if 0 633 /* These messages are temporary debugging aids */ 634 if (vnlru_nowhere < 5) 635 printf("vnlru process getting nowhere..\n"); 636 else if (vnlru_nowhere == 5) 637 printf("vnlru process messages stopped.\n"); 638 #endif 639 vnlru_nowhere++; 640 tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); 641 } 642 } 643 splx(s); 644 } 645 646 static struct kproc_desc vnlru_kp = { 647 "vnlru", 648 vnlru_proc, 649 &vnlruproc 650 }; 651 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &vnlru_kp) 652 653 654 /* 655 * Routines having to do with the management of the vnode table. 656 */ 657 658 /* 659 * Return the next vnode from the free list. 660 */ 661 int 662 getnewvnode(tag, mp, vops, vpp) 663 enum vtagtype tag; 664 struct mount *mp; 665 vop_t **vops; 666 struct vnode **vpp; 667 { 668 int s; 669 struct thread *td = curthread; /* XXX */ 670 struct vnode *vp = NULL; 671 struct mount *vnmp; 672 vm_object_t object; 673 674 s = splbio(); 675 /* 676 * Try to reuse vnodes if we hit the max. This situation only 677 * occurs in certain large-memory (2G+) situations. We cannot 678 * attempt to directly reclaim vnodes due to nasty recursion 679 * problems. 680 */ 681 if (vnlruproc_sig == 0 && numvnodes - freevnodes > desiredvnodes) { 682 vnlruproc_sig = 1; /* avoid unnecessary wakeups */ 683 wakeup(vnlruproc); 684 } 685 686 /* 687 * Attempt to reuse a vnode already on the free list, allocating 688 * a new vnode if we can't find one or if we have not reached a 689 * good minimum for good LRU performance. 690 */ 691 692 mtx_lock(&vnode_free_list_mtx); 693 694 if (freevnodes >= wantfreevnodes && numvnodes >= minvnodes) { 695 int count; 696 697 for (count = 0; count < freevnodes; count++) { 698 vp = TAILQ_FIRST(&vnode_free_list); 699 if (vp == NULL || vp->v_usecount) 700 panic("getnewvnode: free vnode isn't"); 701 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 702 703 /* Don't recycle if we can't get the interlock */ 704 if (!mtx_trylock(&vp->v_interlock)) { 705 vp = NULL; 706 continue; 707 } 708 709 /* We should be able to immediately acquire this */ 710 if (vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE, td) != 0) 711 continue; 712 /* 713 * Don't recycle if we still have cached pages. 714 */ 715 if (VOP_GETVOBJECT(vp, &object) == 0 && 716 (object->resident_page_count || 717 object->ref_count)) { 718 TAILQ_INSERT_TAIL(&vnode_free_list, vp, 719 v_freelist); 720 VOP_UNLOCK(vp, 0, td); 721 vp = NULL; 722 continue; 723 } 724 if (LIST_FIRST(&vp->v_cache_src)) { 725 /* 726 * note: nameileafonly sysctl is temporary, 727 * for debugging only, and will eventually be 728 * removed. 729 */ 730 if (nameileafonly > 0) { 731 /* 732 * Do not reuse namei-cached directory 733 * vnodes that have cached 734 * subdirectories. 735 */ 736 if (cache_leaf_test(vp) < 0) { 737 VOP_UNLOCK(vp, 0, td); 738 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 739 vp = NULL; 740 continue; 741 } 742 } else if (nameileafonly < 0 || 743 vmiodirenable == 0) { 744 /* 745 * Do not reuse namei-cached directory 746 * vnodes if nameileafonly is -1 or 747 * if VMIO backing for directories is 748 * turned off (otherwise we reuse them 749 * too quickly). 750 */ 751 VOP_UNLOCK(vp, 0, td); 752 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 753 vp = NULL; 754 continue; 755 } 756 } 757 /* 758 * Skip over it if its filesystem is being suspended. 759 */ 760 if (vn_start_write(vp, &vnmp, V_NOWAIT) == 0) 761 break; 762 VOP_UNLOCK(vp, 0, td); 763 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 764 vp = NULL; 765 } 766 } 767 if (vp) { 768 vp->v_flag |= VDOOMED; 769 vp->v_flag &= ~VFREE; 770 freevnodes--; 771 mtx_unlock(&vnode_free_list_mtx); 772 cache_purge(vp); 773 if (vp->v_type != VBAD) { 774 VOP_UNLOCK(vp, 0, td); 775 vgone(vp); 776 } else { 777 VOP_UNLOCK(vp, 0, td); 778 } 779 vn_finished_write(vnmp); 780 781 #ifdef INVARIANTS 782 { 783 int s; 784 785 if (vp->v_data) 786 panic("cleaned vnode isn't"); 787 s = splbio(); 788 if (vp->v_numoutput) 789 panic("Clean vnode has pending I/O's"); 790 splx(s); 791 if (vp->v_writecount != 0) 792 panic("Non-zero write count"); 793 } 794 #endif 795 if (vp->v_pollinfo) { 796 mtx_destroy(&vp->v_pollinfo->vpi_lock); 797 uma_zfree(vnodepoll_zone, vp->v_pollinfo); 798 } 799 vp->v_pollinfo = NULL; 800 vp->v_flag = 0; 801 vp->v_lastw = 0; 802 vp->v_lasta = 0; 803 vp->v_cstart = 0; 804 vp->v_clen = 0; 805 vp->v_socket = 0; 806 KASSERT(vp->v_cleanblkroot == NULL, ("cleanblkroot not NULL")); 807 KASSERT(vp->v_dirtyblkroot == NULL, ("dirtyblkroot not NULL")); 808 } else { 809 mtx_unlock(&vnode_free_list_mtx); 810 vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK); 811 bzero((char *) vp, sizeof *vp); 812 mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); 813 vp->v_dd = vp; 814 cache_purge(vp); 815 LIST_INIT(&vp->v_cache_src); 816 TAILQ_INIT(&vp->v_cache_dst); 817 numvnodes++; 818 } 819 820 TAILQ_INIT(&vp->v_cleanblkhd); 821 TAILQ_INIT(&vp->v_dirtyblkhd); 822 vp->v_type = VNON; 823 vp->v_tag = tag; 824 vp->v_op = vops; 825 lockinit(&vp->v_lock, PVFS, "vnlock", VLKTIMEOUT, LK_NOPAUSE); 826 insmntque(vp, mp); 827 *vpp = vp; 828 vp->v_usecount = 1; 829 vp->v_data = 0; 830 831 splx(s); 832 833 #if 0 834 vnodeallocs++; 835 if (vnodeallocs % vnoderecycleperiod == 0 && 836 freevnodes < vnoderecycleminfreevn && 837 vnoderecyclemintotalvn < numvnodes) { 838 /* Recycle vnodes. */ 839 cache_purgeleafdirs(vnoderecyclenumber); 840 } 841 #endif 842 843 return (0); 844 } 845 846 /* 847 * Move a vnode from one mount queue to another. 848 */ 849 static void 850 insmntque(vp, mp) 851 register struct vnode *vp; 852 register struct mount *mp; 853 { 854 855 mtx_lock(&mntvnode_mtx); 856 /* 857 * Delete from old mount point vnode list, if on one. 858 */ 859 if (vp->v_mount != NULL) 860 TAILQ_REMOVE(&vp->v_mount->mnt_nvnodelist, vp, v_nmntvnodes); 861 /* 862 * Insert into list of vnodes for the new mount point, if available. 863 */ 864 if ((vp->v_mount = mp) == NULL) { 865 mtx_unlock(&mntvnode_mtx); 866 return; 867 } 868 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 869 mtx_unlock(&mntvnode_mtx); 870 } 871 872 /* 873 * Update outstanding I/O count and do wakeup if requested. 874 */ 875 void 876 vwakeup(bp) 877 register struct buf *bp; 878 { 879 register struct vnode *vp; 880 881 bp->b_flags &= ~B_WRITEINPROG; 882 if ((vp = bp->b_vp)) { 883 vp->v_numoutput--; 884 if (vp->v_numoutput < 0) 885 panic("vwakeup: neg numoutput"); 886 if ((vp->v_numoutput == 0) && (vp->v_flag & VBWAIT)) { 887 vp->v_flag &= ~VBWAIT; 888 wakeup(&vp->v_numoutput); 889 } 890 } 891 } 892 893 /* 894 * Flush out and invalidate all buffers associated with a vnode. 895 * Called with the underlying object locked. 896 */ 897 int 898 vinvalbuf(vp, flags, cred, td, slpflag, slptimeo) 899 register struct vnode *vp; 900 int flags; 901 struct ucred *cred; 902 struct thread *td; 903 int slpflag, slptimeo; 904 { 905 register struct buf *bp; 906 struct buf *nbp, *blist; 907 int s, error; 908 vm_object_t object; 909 910 GIANT_REQUIRED; 911 912 if (flags & V_SAVE) { 913 s = splbio(); 914 while (vp->v_numoutput) { 915 vp->v_flag |= VBWAIT; 916 error = tsleep(&vp->v_numoutput, 917 slpflag | (PRIBIO + 1), "vinvlbuf", slptimeo); 918 if (error) { 919 splx(s); 920 return (error); 921 } 922 } 923 if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) { 924 splx(s); 925 if ((error = VOP_FSYNC(vp, cred, MNT_WAIT, td)) != 0) 926 return (error); 927 s = splbio(); 928 if (vp->v_numoutput > 0 || 929 !TAILQ_EMPTY(&vp->v_dirtyblkhd)) 930 panic("vinvalbuf: dirty bufs"); 931 } 932 splx(s); 933 } 934 s = splbio(); 935 for (;;) { 936 blist = TAILQ_FIRST(&vp->v_cleanblkhd); 937 if (!blist) 938 blist = TAILQ_FIRST(&vp->v_dirtyblkhd); 939 if (!blist) 940 break; 941 942 for (bp = blist; bp; bp = nbp) { 943 nbp = TAILQ_NEXT(bp, b_vnbufs); 944 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) { 945 error = BUF_TIMELOCK(bp, 946 LK_EXCLUSIVE | LK_SLEEPFAIL, 947 "vinvalbuf", slpflag, slptimeo); 948 if (error == ENOLCK) 949 break; 950 splx(s); 951 return (error); 952 } 953 /* 954 * XXX Since there are no node locks for NFS, I 955 * believe there is a slight chance that a delayed 956 * write will occur while sleeping just above, so 957 * check for it. Note that vfs_bio_awrite expects 958 * buffers to reside on a queue, while BUF_WRITE and 959 * brelse do not. 960 */ 961 if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && 962 (flags & V_SAVE)) { 963 964 if (bp->b_vp == vp) { 965 if (bp->b_flags & B_CLUSTEROK) { 966 BUF_UNLOCK(bp); 967 vfs_bio_awrite(bp); 968 } else { 969 bremfree(bp); 970 bp->b_flags |= B_ASYNC; 971 BUF_WRITE(bp); 972 } 973 } else { 974 bremfree(bp); 975 (void) BUF_WRITE(bp); 976 } 977 break; 978 } 979 bremfree(bp); 980 bp->b_flags |= (B_INVAL | B_NOCACHE | B_RELBUF); 981 bp->b_flags &= ~B_ASYNC; 982 brelse(bp); 983 } 984 } 985 986 /* 987 * Wait for I/O to complete. XXX needs cleaning up. The vnode can 988 * have write I/O in-progress but if there is a VM object then the 989 * VM object can also have read-I/O in-progress. 990 */ 991 do { 992 while (vp->v_numoutput > 0) { 993 vp->v_flag |= VBWAIT; 994 tsleep(&vp->v_numoutput, PVM, "vnvlbv", 0); 995 } 996 if (VOP_GETVOBJECT(vp, &object) == 0) { 997 while (object->paging_in_progress) 998 vm_object_pip_sleep(object, "vnvlbx"); 999 } 1000 } while (vp->v_numoutput > 0); 1001 1002 splx(s); 1003 1004 /* 1005 * Destroy the copy in the VM cache, too. 1006 */ 1007 mtx_lock(&vp->v_interlock); 1008 if (VOP_GETVOBJECT(vp, &object) == 0) { 1009 vm_object_page_remove(object, 0, 0, 1010 (flags & V_SAVE) ? TRUE : FALSE); 1011 } 1012 mtx_unlock(&vp->v_interlock); 1013 1014 if (!TAILQ_EMPTY(&vp->v_dirtyblkhd) || !TAILQ_EMPTY(&vp->v_cleanblkhd)) 1015 panic("vinvalbuf: flush failed"); 1016 return (0); 1017 } 1018 1019 /* 1020 * Truncate a file's buffer and pages to a specified length. This 1021 * is in lieu of the old vinvalbuf mechanism, which performed unneeded 1022 * sync activity. 1023 */ 1024 int 1025 vtruncbuf(vp, cred, td, length, blksize) 1026 register struct vnode *vp; 1027 struct ucred *cred; 1028 struct thread *td; 1029 off_t length; 1030 int blksize; 1031 { 1032 register struct buf *bp; 1033 struct buf *nbp; 1034 int s, anyfreed; 1035 int trunclbn; 1036 1037 /* 1038 * Round up to the *next* lbn. 1039 */ 1040 trunclbn = (length + blksize - 1) / blksize; 1041 1042 s = splbio(); 1043 restart: 1044 anyfreed = 1; 1045 for (;anyfreed;) { 1046 anyfreed = 0; 1047 for (bp = TAILQ_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) { 1048 nbp = TAILQ_NEXT(bp, b_vnbufs); 1049 if (bp->b_lblkno >= trunclbn) { 1050 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) { 1051 BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL); 1052 goto restart; 1053 } else { 1054 bremfree(bp); 1055 bp->b_flags |= (B_INVAL | B_RELBUF); 1056 bp->b_flags &= ~B_ASYNC; 1057 brelse(bp); 1058 anyfreed = 1; 1059 } 1060 if (nbp && 1061 (((nbp->b_xflags & BX_VNCLEAN) == 0) || 1062 (nbp->b_vp != vp) || 1063 (nbp->b_flags & B_DELWRI))) { 1064 goto restart; 1065 } 1066 } 1067 } 1068 1069 for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { 1070 nbp = TAILQ_NEXT(bp, b_vnbufs); 1071 if (bp->b_lblkno >= trunclbn) { 1072 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) { 1073 BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL); 1074 goto restart; 1075 } else { 1076 bremfree(bp); 1077 bp->b_flags |= (B_INVAL | B_RELBUF); 1078 bp->b_flags &= ~B_ASYNC; 1079 brelse(bp); 1080 anyfreed = 1; 1081 } 1082 if (nbp && 1083 (((nbp->b_xflags & BX_VNDIRTY) == 0) || 1084 (nbp->b_vp != vp) || 1085 (nbp->b_flags & B_DELWRI) == 0)) { 1086 goto restart; 1087 } 1088 } 1089 } 1090 } 1091 1092 if (length > 0) { 1093 restartsync: 1094 for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { 1095 nbp = TAILQ_NEXT(bp, b_vnbufs); 1096 if ((bp->b_flags & B_DELWRI) && (bp->b_lblkno < 0)) { 1097 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) { 1098 BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL); 1099 goto restart; 1100 } else { 1101 bremfree(bp); 1102 if (bp->b_vp == vp) { 1103 bp->b_flags |= B_ASYNC; 1104 } else { 1105 bp->b_flags &= ~B_ASYNC; 1106 } 1107 BUF_WRITE(bp); 1108 } 1109 goto restartsync; 1110 } 1111 1112 } 1113 } 1114 1115 while (vp->v_numoutput > 0) { 1116 vp->v_flag |= VBWAIT; 1117 tsleep(&vp->v_numoutput, PVM, "vbtrunc", 0); 1118 } 1119 1120 splx(s); 1121 1122 vnode_pager_setsize(vp, length); 1123 1124 return (0); 1125 } 1126 1127 /* 1128 * buf_splay() - splay tree core for the clean/dirty list of buffers in 1129 * a vnode. 1130 * 1131 * NOTE: We have to deal with the special case of a background bitmap 1132 * buffer, a situation where two buffers will have the same logical 1133 * block offset. We want (1) only the foreground buffer to be accessed 1134 * in a lookup and (2) must differentiate between the foreground and 1135 * background buffer in the splay tree algorithm because the splay 1136 * tree cannot normally handle multiple entities with the same 'index'. 1137 * We accomplish this by adding differentiating flags to the splay tree's 1138 * numerical domain. 1139 */ 1140 static 1141 struct buf * 1142 buf_splay(daddr_t lblkno, b_xflags_t xflags, struct buf *root) 1143 { 1144 struct buf dummy; 1145 struct buf *lefttreemax, *righttreemin, *y; 1146 1147 if (root == NULL) 1148 return (NULL); 1149 lefttreemax = righttreemin = &dummy; 1150 for (;;) { 1151 if (lblkno < root->b_lblkno || 1152 (lblkno == root->b_lblkno && 1153 (xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1154 if ((y = root->b_left) == NULL) 1155 break; 1156 if (lblkno < y->b_lblkno) { 1157 /* Rotate right. */ 1158 root->b_left = y->b_right; 1159 y->b_right = root; 1160 root = y; 1161 if ((y = root->b_left) == NULL) 1162 break; 1163 } 1164 /* Link into the new root's right tree. */ 1165 righttreemin->b_left = root; 1166 righttreemin = root; 1167 } else if (lblkno > root->b_lblkno || 1168 (lblkno == root->b_lblkno && 1169 (xflags & BX_BKGRDMARKER) > (root->b_xflags & BX_BKGRDMARKER))) { 1170 if ((y = root->b_right) == NULL) 1171 break; 1172 if (lblkno > y->b_lblkno) { 1173 /* Rotate left. */ 1174 root->b_right = y->b_left; 1175 y->b_left = root; 1176 root = y; 1177 if ((y = root->b_right) == NULL) 1178 break; 1179 } 1180 /* Link into the new root's left tree. */ 1181 lefttreemax->b_right = root; 1182 lefttreemax = root; 1183 } else { 1184 break; 1185 } 1186 root = y; 1187 } 1188 /* Assemble the new root. */ 1189 lefttreemax->b_right = root->b_left; 1190 righttreemin->b_left = root->b_right; 1191 root->b_left = dummy.b_right; 1192 root->b_right = dummy.b_left; 1193 return (root); 1194 } 1195 1196 static 1197 void 1198 buf_vlist_remove(struct buf *bp) 1199 { 1200 struct vnode *vp = bp->b_vp; 1201 struct buf *root; 1202 1203 if (bp->b_xflags & BX_VNDIRTY) { 1204 if (bp != vp->v_dirtyblkroot) { 1205 root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_dirtyblkroot); 1206 KASSERT(root == bp, ("splay lookup failed during dirty remove")); 1207 } 1208 if (bp->b_left == NULL) { 1209 root = bp->b_right; 1210 } else { 1211 root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left); 1212 root->b_right = bp->b_right; 1213 } 1214 vp->v_dirtyblkroot = root; 1215 TAILQ_REMOVE(&vp->v_dirtyblkhd, bp, b_vnbufs); 1216 } else { 1217 /* KASSERT(bp->b_xflags & BX_VNCLEAN, ("bp wasn't clean")); */ 1218 if (bp != vp->v_cleanblkroot) { 1219 root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_cleanblkroot); 1220 KASSERT(root == bp, ("splay lookup failed during clean remove")); 1221 } 1222 if (bp->b_left == NULL) { 1223 root = bp->b_right; 1224 } else { 1225 root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left); 1226 root->b_right = bp->b_right; 1227 } 1228 vp->v_cleanblkroot = root; 1229 TAILQ_REMOVE(&vp->v_cleanblkhd, bp, b_vnbufs); 1230 } 1231 bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); 1232 } 1233 1234 /* 1235 * Add the buffer to the sorted clean or dirty block list using a 1236 * splay tree algorithm. 1237 * 1238 * NOTE: xflags is passed as a constant, optimizing this inline function! 1239 */ 1240 static 1241 void 1242 buf_vlist_add(struct buf *bp, struct vnode *vp, b_xflags_t xflags) 1243 { 1244 struct buf *root; 1245 1246 bp->b_xflags |= xflags; 1247 if (xflags & BX_VNDIRTY) { 1248 root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_dirtyblkroot); 1249 if (root == NULL) { 1250 bp->b_left = NULL; 1251 bp->b_right = NULL; 1252 TAILQ_INSERT_TAIL(&vp->v_dirtyblkhd, bp, b_vnbufs); 1253 } else if (bp->b_lblkno < root->b_lblkno || 1254 (bp->b_lblkno == root->b_lblkno && 1255 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1256 bp->b_left = root->b_left; 1257 bp->b_right = root; 1258 root->b_left = NULL; 1259 TAILQ_INSERT_BEFORE(root, bp, b_vnbufs); 1260 } else { 1261 bp->b_right = root->b_right; 1262 bp->b_left = root; 1263 root->b_right = NULL; 1264 TAILQ_INSERT_AFTER(&vp->v_dirtyblkhd, 1265 root, bp, b_vnbufs); 1266 } 1267 vp->v_dirtyblkroot = bp; 1268 } else { 1269 /* KASSERT(xflags & BX_VNCLEAN, ("xflags not clean")); */ 1270 root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_cleanblkroot); 1271 if (root == NULL) { 1272 bp->b_left = NULL; 1273 bp->b_right = NULL; 1274 TAILQ_INSERT_TAIL(&vp->v_cleanblkhd, bp, b_vnbufs); 1275 } else if (bp->b_lblkno < root->b_lblkno || 1276 (bp->b_lblkno == root->b_lblkno && 1277 (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { 1278 bp->b_left = root->b_left; 1279 bp->b_right = root; 1280 root->b_left = NULL; 1281 TAILQ_INSERT_BEFORE(root, bp, b_vnbufs); 1282 } else { 1283 bp->b_right = root->b_right; 1284 bp->b_left = root; 1285 root->b_right = NULL; 1286 TAILQ_INSERT_AFTER(&vp->v_cleanblkhd, 1287 root, bp, b_vnbufs); 1288 } 1289 vp->v_cleanblkroot = bp; 1290 } 1291 } 1292 1293 #ifndef USE_BUFHASH 1294 1295 /* 1296 * Lookup a buffer using the splay tree. Note that we specifically avoid 1297 * shadow buffers used in background bitmap writes. 1298 * 1299 * This code isn't quite efficient as it could be because we are maintaining 1300 * two sorted lists and do not know which list the block resides in. 1301 */ 1302 struct buf * 1303 gbincore(struct vnode *vp, daddr_t lblkno) 1304 { 1305 struct buf *bp; 1306 1307 GIANT_REQUIRED; 1308 1309 bp = vp->v_cleanblkroot = buf_splay(lblkno, 0, vp->v_cleanblkroot); 1310 if (bp && bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1311 return(bp); 1312 bp = vp->v_dirtyblkroot = buf_splay(lblkno, 0, vp->v_dirtyblkroot); 1313 if (bp && bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) 1314 return(bp); 1315 return(NULL); 1316 } 1317 1318 #endif 1319 1320 /* 1321 * Associate a buffer with a vnode. 1322 */ 1323 void 1324 bgetvp(vp, bp) 1325 register struct vnode *vp; 1326 register struct buf *bp; 1327 { 1328 int s; 1329 1330 KASSERT(bp->b_vp == NULL, ("bgetvp: not free")); 1331 1332 KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, 1333 ("bgetvp: bp already attached! %p", bp)); 1334 1335 vhold(vp); 1336 bp->b_vp = vp; 1337 bp->b_dev = vn_todev(vp); 1338 /* 1339 * Insert onto list for new vnode. 1340 */ 1341 s = splbio(); 1342 buf_vlist_add(bp, vp, BX_VNCLEAN); 1343 splx(s); 1344 } 1345 1346 /* 1347 * Disassociate a buffer from a vnode. 1348 */ 1349 void 1350 brelvp(bp) 1351 register struct buf *bp; 1352 { 1353 struct vnode *vp; 1354 int s; 1355 1356 KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); 1357 1358 /* 1359 * Delete from old vnode list, if on one. 1360 */ 1361 vp = bp->b_vp; 1362 s = splbio(); 1363 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) 1364 buf_vlist_remove(bp); 1365 if ((vp->v_flag & VONWORKLST) && TAILQ_EMPTY(&vp->v_dirtyblkhd)) { 1366 vp->v_flag &= ~VONWORKLST; 1367 LIST_REMOVE(vp, v_synclist); 1368 } 1369 splx(s); 1370 bp->b_vp = (struct vnode *) 0; 1371 vdrop(vp); 1372 if (bp->b_object) 1373 bp->b_object = NULL; 1374 } 1375 1376 /* 1377 * Add an item to the syncer work queue. 1378 */ 1379 static void 1380 vn_syncer_add_to_worklist(struct vnode *vp, int delay) 1381 { 1382 int s, slot; 1383 1384 s = splbio(); 1385 1386 if (vp->v_flag & VONWORKLST) { 1387 LIST_REMOVE(vp, v_synclist); 1388 } 1389 1390 if (delay > syncer_maxdelay - 2) 1391 delay = syncer_maxdelay - 2; 1392 slot = (syncer_delayno + delay) & syncer_mask; 1393 1394 LIST_INSERT_HEAD(&syncer_workitem_pending[slot], vp, v_synclist); 1395 vp->v_flag |= VONWORKLST; 1396 splx(s); 1397 } 1398 1399 struct proc *updateproc; 1400 static void sched_sync(void); 1401 static struct kproc_desc up_kp = { 1402 "syncer", 1403 sched_sync, 1404 &updateproc 1405 }; 1406 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp) 1407 1408 /* 1409 * System filesystem synchronizer daemon. 1410 */ 1411 void 1412 sched_sync(void) 1413 { 1414 struct synclist *slp; 1415 struct vnode *vp; 1416 struct mount *mp; 1417 long starttime; 1418 int s; 1419 struct thread *td = FIRST_THREAD_IN_PROC(updateproc); /* XXXKSE */ 1420 1421 mtx_lock(&Giant); 1422 1423 EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, td->td_proc, 1424 SHUTDOWN_PRI_LAST); 1425 1426 for (;;) { 1427 kthread_suspend_check(td->td_proc); 1428 1429 starttime = time_second; 1430 1431 /* 1432 * Push files whose dirty time has expired. Be careful 1433 * of interrupt race on slp queue. 1434 */ 1435 s = splbio(); 1436 slp = &syncer_workitem_pending[syncer_delayno]; 1437 syncer_delayno += 1; 1438 if (syncer_delayno == syncer_maxdelay) 1439 syncer_delayno = 0; 1440 splx(s); 1441 1442 while ((vp = LIST_FIRST(slp)) != NULL) { 1443 if (VOP_ISLOCKED(vp, NULL) == 0 && 1444 vn_start_write(vp, &mp, V_NOWAIT) == 0) { 1445 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1446 (void) VOP_FSYNC(vp, td->td_ucred, MNT_LAZY, td); 1447 VOP_UNLOCK(vp, 0, td); 1448 vn_finished_write(mp); 1449 } 1450 s = splbio(); 1451 if (LIST_FIRST(slp) == vp) { 1452 /* 1453 * Note: v_tag VT_VFS vps can remain on the 1454 * worklist too with no dirty blocks, but 1455 * since sync_fsync() moves it to a different 1456 * slot we are safe. 1457 */ 1458 if (TAILQ_EMPTY(&vp->v_dirtyblkhd) && 1459 !vn_isdisk(vp, NULL)) 1460 panic("sched_sync: fsync failed vp %p tag %d", vp, vp->v_tag); 1461 /* 1462 * Put us back on the worklist. The worklist 1463 * routine will remove us from our current 1464 * position and then add us back in at a later 1465 * position. 1466 */ 1467 vn_syncer_add_to_worklist(vp, syncdelay); 1468 } 1469 splx(s); 1470 } 1471 1472 /* 1473 * Do soft update processing. 1474 */ 1475 if (softdep_process_worklist_hook != NULL) 1476 (*softdep_process_worklist_hook)(NULL); 1477 1478 /* 1479 * The variable rushjob allows the kernel to speed up the 1480 * processing of the filesystem syncer process. A rushjob 1481 * value of N tells the filesystem syncer to process the next 1482 * N seconds worth of work on its queue ASAP. Currently rushjob 1483 * is used by the soft update code to speed up the filesystem 1484 * syncer process when the incore state is getting so far 1485 * ahead of the disk that the kernel memory pool is being 1486 * threatened with exhaustion. 1487 */ 1488 if (rushjob > 0) { 1489 rushjob -= 1; 1490 continue; 1491 } 1492 /* 1493 * If it has taken us less than a second to process the 1494 * current work, then wait. Otherwise start right over 1495 * again. We can still lose time if any single round 1496 * takes more than two seconds, but it does not really 1497 * matter as we are just trying to generally pace the 1498 * filesystem activity. 1499 */ 1500 if (time_second == starttime) 1501 tsleep(&lbolt, PPAUSE, "syncer", 0); 1502 } 1503 } 1504 1505 /* 1506 * Request the syncer daemon to speed up its work. 1507 * We never push it to speed up more than half of its 1508 * normal turn time, otherwise it could take over the cpu. 1509 * XXXKSE only one update? 1510 */ 1511 int 1512 speedup_syncer() 1513 { 1514 1515 mtx_lock_spin(&sched_lock); 1516 if (FIRST_THREAD_IN_PROC(updateproc)->td_wchan == &lbolt) /* XXXKSE */ 1517 setrunnable(FIRST_THREAD_IN_PROC(updateproc)); 1518 mtx_unlock_spin(&sched_lock); 1519 if (rushjob < syncdelay / 2) { 1520 rushjob += 1; 1521 stat_rush_requests += 1; 1522 return (1); 1523 } 1524 return(0); 1525 } 1526 1527 /* 1528 * Associate a p-buffer with a vnode. 1529 * 1530 * Also sets B_PAGING flag to indicate that vnode is not fully associated 1531 * with the buffer. i.e. the bp has not been linked into the vnode or 1532 * ref-counted. 1533 */ 1534 void 1535 pbgetvp(vp, bp) 1536 register struct vnode *vp; 1537 register struct buf *bp; 1538 { 1539 1540 KASSERT(bp->b_vp == NULL, ("pbgetvp: not free")); 1541 1542 bp->b_vp = vp; 1543 bp->b_flags |= B_PAGING; 1544 bp->b_dev = vn_todev(vp); 1545 } 1546 1547 /* 1548 * Disassociate a p-buffer from a vnode. 1549 */ 1550 void 1551 pbrelvp(bp) 1552 register struct buf *bp; 1553 { 1554 1555 KASSERT(bp->b_vp != NULL, ("pbrelvp: NULL")); 1556 1557 /* XXX REMOVE ME */ 1558 if (TAILQ_NEXT(bp, b_vnbufs) != NULL) { 1559 panic( 1560 "relpbuf(): b_vp was probably reassignbuf()d %p %x", 1561 bp, 1562 (int)bp->b_flags 1563 ); 1564 } 1565 bp->b_vp = (struct vnode *) 0; 1566 bp->b_flags &= ~B_PAGING; 1567 } 1568 1569 /* 1570 * Reassign a buffer from one vnode to another. 1571 * Used to assign file specific control information 1572 * (indirect blocks) to the vnode to which they belong. 1573 */ 1574 void 1575 reassignbuf(bp, newvp) 1576 register struct buf *bp; 1577 register struct vnode *newvp; 1578 { 1579 int delay; 1580 int s; 1581 1582 if (newvp == NULL) { 1583 printf("reassignbuf: NULL"); 1584 return; 1585 } 1586 ++reassignbufcalls; 1587 1588 /* 1589 * B_PAGING flagged buffers cannot be reassigned because their vp 1590 * is not fully linked in. 1591 */ 1592 if (bp->b_flags & B_PAGING) 1593 panic("cannot reassign paging buffer"); 1594 1595 s = splbio(); 1596 /* 1597 * Delete from old vnode list, if on one. 1598 */ 1599 if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) { 1600 buf_vlist_remove(bp); 1601 if (bp->b_vp != newvp) { 1602 vdrop(bp->b_vp); 1603 bp->b_vp = NULL; /* for clarification */ 1604 } 1605 } 1606 /* 1607 * If dirty, put on list of dirty buffers; otherwise insert onto list 1608 * of clean buffers. 1609 */ 1610 if (bp->b_flags & B_DELWRI) { 1611 if ((newvp->v_flag & VONWORKLST) == 0) { 1612 switch (newvp->v_type) { 1613 case VDIR: 1614 delay = dirdelay; 1615 break; 1616 case VCHR: 1617 if (newvp->v_rdev->si_mountpoint != NULL) { 1618 delay = metadelay; 1619 break; 1620 } 1621 /* fall through */ 1622 default: 1623 delay = filedelay; 1624 } 1625 vn_syncer_add_to_worklist(newvp, delay); 1626 } 1627 buf_vlist_add(bp, newvp, BX_VNDIRTY); 1628 } else { 1629 buf_vlist_add(bp, newvp, BX_VNCLEAN); 1630 1631 if ((newvp->v_flag & VONWORKLST) && 1632 TAILQ_EMPTY(&newvp->v_dirtyblkhd)) { 1633 newvp->v_flag &= ~VONWORKLST; 1634 LIST_REMOVE(newvp, v_synclist); 1635 } 1636 } 1637 if (bp->b_vp != newvp) { 1638 bp->b_vp = newvp; 1639 vhold(bp->b_vp); 1640 } 1641 splx(s); 1642 } 1643 1644 /* 1645 * Create a vnode for a device. 1646 * Used for mounting the root filesystem. 1647 */ 1648 int 1649 bdevvp(dev, vpp) 1650 dev_t dev; 1651 struct vnode **vpp; 1652 { 1653 register struct vnode *vp; 1654 struct vnode *nvp; 1655 int error; 1656 1657 if (dev == NODEV) { 1658 *vpp = NULLVP; 1659 return (ENXIO); 1660 } 1661 if (vfinddev(dev, VCHR, vpp)) 1662 return (0); 1663 error = getnewvnode(VT_NON, (struct mount *)0, spec_vnodeop_p, &nvp); 1664 if (error) { 1665 *vpp = NULLVP; 1666 return (error); 1667 } 1668 vp = nvp; 1669 vp->v_type = VCHR; 1670 addalias(vp, dev); 1671 *vpp = vp; 1672 return (0); 1673 } 1674 1675 /* 1676 * Add vnode to the alias list hung off the dev_t. 1677 * 1678 * The reason for this gunk is that multiple vnodes can reference 1679 * the same physical device, so checking vp->v_usecount to see 1680 * how many users there are is inadequate; the v_usecount for 1681 * the vnodes need to be accumulated. vcount() does that. 1682 */ 1683 struct vnode * 1684 addaliasu(nvp, nvp_rdev) 1685 struct vnode *nvp; 1686 udev_t nvp_rdev; 1687 { 1688 struct vnode *ovp; 1689 vop_t **ops; 1690 dev_t dev; 1691 1692 if (nvp->v_type == VBLK) 1693 return (nvp); 1694 if (nvp->v_type != VCHR) 1695 panic("addaliasu on non-special vnode"); 1696 dev = udev2dev(nvp_rdev, 0); 1697 /* 1698 * Check to see if we have a bdevvp vnode with no associated 1699 * filesystem. If so, we want to associate the filesystem of 1700 * the new newly instigated vnode with the bdevvp vnode and 1701 * discard the newly created vnode rather than leaving the 1702 * bdevvp vnode lying around with no associated filesystem. 1703 */ 1704 if (vfinddev(dev, nvp->v_type, &ovp) == 0 || ovp->v_data != NULL) { 1705 addalias(nvp, dev); 1706 return (nvp); 1707 } 1708 /* 1709 * Discard unneeded vnode, but save its node specific data. 1710 * Note that if there is a lock, it is carried over in the 1711 * node specific data to the replacement vnode. 1712 */ 1713 vref(ovp); 1714 ovp->v_data = nvp->v_data; 1715 ovp->v_tag = nvp->v_tag; 1716 nvp->v_data = NULL; 1717 lockinit(&ovp->v_lock, PVFS, nvp->v_lock.lk_wmesg, 1718 nvp->v_lock.lk_timo, nvp->v_lock.lk_flags & LK_EXTFLG_MASK); 1719 if (nvp->v_vnlock) 1720 ovp->v_vnlock = &ovp->v_lock; 1721 ops = ovp->v_op; 1722 ovp->v_op = nvp->v_op; 1723 if (VOP_ISLOCKED(nvp, curthread)) { 1724 VOP_UNLOCK(nvp, 0, curthread); 1725 vn_lock(ovp, LK_EXCLUSIVE | LK_RETRY, curthread); 1726 } 1727 nvp->v_op = ops; 1728 insmntque(ovp, nvp->v_mount); 1729 vrele(nvp); 1730 vgone(nvp); 1731 return (ovp); 1732 } 1733 1734 /* This is a local helper function that do the same as addaliasu, but for a 1735 * dev_t instead of an udev_t. */ 1736 static void 1737 addalias(nvp, dev) 1738 struct vnode *nvp; 1739 dev_t dev; 1740 { 1741 1742 KASSERT(nvp->v_type == VCHR, ("addalias on non-special vnode")); 1743 nvp->v_rdev = dev; 1744 mtx_lock(&spechash_mtx); 1745 SLIST_INSERT_HEAD(&dev->si_hlist, nvp, v_specnext); 1746 mtx_unlock(&spechash_mtx); 1747 } 1748 1749 /* 1750 * Grab a particular vnode from the free list, increment its 1751 * reference count and lock it. The vnode lock bit is set if the 1752 * vnode is being eliminated in vgone. The process is awakened 1753 * when the transition is completed, and an error returned to 1754 * indicate that the vnode is no longer usable (possibly having 1755 * been changed to a new filesystem type). 1756 */ 1757 int 1758 vget(vp, flags, td) 1759 register struct vnode *vp; 1760 int flags; 1761 struct thread *td; 1762 { 1763 int error; 1764 1765 /* 1766 * If the vnode is in the process of being cleaned out for 1767 * another use, we wait for the cleaning to finish and then 1768 * return failure. Cleaning is determined by checking that 1769 * the VXLOCK flag is set. 1770 */ 1771 if ((flags & LK_INTERLOCK) == 0) 1772 mtx_lock(&vp->v_interlock); 1773 if (vp->v_flag & VXLOCK) { 1774 if (vp->v_vxproc == curthread) { 1775 #if 0 1776 /* this can now occur in normal operation */ 1777 log(LOG_INFO, "VXLOCK interlock avoided\n"); 1778 #endif 1779 } else { 1780 vp->v_flag |= VXWANT; 1781 msleep(vp, &vp->v_interlock, PINOD | PDROP, "vget", 0); 1782 return (ENOENT); 1783 } 1784 } 1785 1786 vp->v_usecount++; 1787 1788 if (VSHOULDBUSY(vp)) 1789 vbusy(vp); 1790 if (flags & LK_TYPE_MASK) { 1791 if ((error = vn_lock(vp, flags | LK_INTERLOCK, td)) != 0) { 1792 /* 1793 * must expand vrele here because we do not want 1794 * to call VOP_INACTIVE if the reference count 1795 * drops back to zero since it was never really 1796 * active. We must remove it from the free list 1797 * before sleeping so that multiple processes do 1798 * not try to recycle it. 1799 */ 1800 mtx_lock(&vp->v_interlock); 1801 vp->v_usecount--; 1802 if (VSHOULDFREE(vp)) 1803 vfree(vp); 1804 else 1805 vlruvp(vp); 1806 mtx_unlock(&vp->v_interlock); 1807 } 1808 return (error); 1809 } 1810 mtx_unlock(&vp->v_interlock); 1811 return (0); 1812 } 1813 1814 /* 1815 * Increase the reference count of a vnode. 1816 */ 1817 void 1818 vref(struct vnode *vp) 1819 { 1820 mtx_lock(&vp->v_interlock); 1821 vp->v_usecount++; 1822 mtx_unlock(&vp->v_interlock); 1823 } 1824 1825 /* 1826 * Vnode put/release. 1827 * If count drops to zero, call inactive routine and return to freelist. 1828 */ 1829 void 1830 vrele(vp) 1831 struct vnode *vp; 1832 { 1833 struct thread *td = curthread; /* XXX */ 1834 1835 KASSERT(vp != NULL, ("vrele: null vp")); 1836 1837 mtx_lock(&vp->v_interlock); 1838 1839 /* Skip this v_writecount check if we're going to panic below. */ 1840 KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, 1841 ("vrele: missed vn_close")); 1842 1843 if (vp->v_usecount > 1) { 1844 1845 vp->v_usecount--; 1846 mtx_unlock(&vp->v_interlock); 1847 1848 return; 1849 } 1850 1851 if (vp->v_usecount == 1) { 1852 vp->v_usecount--; 1853 /* 1854 * We must call VOP_INACTIVE with the node locked. 1855 * If we are doing a vput, the node is already locked, 1856 * but, in the case of vrele, we must explicitly lock 1857 * the vnode before calling VOP_INACTIVE. 1858 */ 1859 if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, td) == 0) 1860 VOP_INACTIVE(vp, td); 1861 if (VSHOULDFREE(vp)) 1862 vfree(vp); 1863 else 1864 vlruvp(vp); 1865 1866 } else { 1867 #ifdef DIAGNOSTIC 1868 vprint("vrele: negative ref count", vp); 1869 mtx_unlock(&vp->v_interlock); 1870 #endif 1871 panic("vrele: negative ref cnt"); 1872 } 1873 } 1874 1875 /* 1876 * Release an already locked vnode. This give the same effects as 1877 * unlock+vrele(), but takes less time and avoids releasing and 1878 * re-aquiring the lock (as vrele() aquires the lock internally.) 1879 */ 1880 void 1881 vput(vp) 1882 struct vnode *vp; 1883 { 1884 struct thread *td = curthread; /* XXX */ 1885 1886 GIANT_REQUIRED; 1887 1888 KASSERT(vp != NULL, ("vput: null vp")); 1889 mtx_lock(&vp->v_interlock); 1890 /* Skip this v_writecount check if we're going to panic below. */ 1891 KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, 1892 ("vput: missed vn_close")); 1893 1894 if (vp->v_usecount > 1) { 1895 vp->v_usecount--; 1896 VOP_UNLOCK(vp, LK_INTERLOCK, td); 1897 return; 1898 } 1899 1900 if (vp->v_usecount == 1) { 1901 vp->v_usecount--; 1902 /* 1903 * We must call VOP_INACTIVE with the node locked. 1904 * If we are doing a vput, the node is already locked, 1905 * so we just need to release the vnode mutex. 1906 */ 1907 mtx_unlock(&vp->v_interlock); 1908 VOP_INACTIVE(vp, td); 1909 if (VSHOULDFREE(vp)) 1910 vfree(vp); 1911 else 1912 vlruvp(vp); 1913 1914 } else { 1915 #ifdef DIAGNOSTIC 1916 vprint("vput: negative ref count", vp); 1917 #endif 1918 panic("vput: negative ref cnt"); 1919 } 1920 } 1921 1922 /* 1923 * Somebody doesn't want the vnode recycled. 1924 */ 1925 void 1926 vhold(vp) 1927 register struct vnode *vp; 1928 { 1929 int s; 1930 1931 s = splbio(); 1932 vp->v_holdcnt++; 1933 if (VSHOULDBUSY(vp)) 1934 vbusy(vp); 1935 splx(s); 1936 } 1937 1938 /* 1939 * Note that there is one less who cares about this vnode. vdrop() is the 1940 * opposite of vhold(). 1941 */ 1942 void 1943 vdrop(vp) 1944 register struct vnode *vp; 1945 { 1946 int s; 1947 1948 s = splbio(); 1949 if (vp->v_holdcnt <= 0) 1950 panic("vdrop: holdcnt"); 1951 vp->v_holdcnt--; 1952 if (VSHOULDFREE(vp)) 1953 vfree(vp); 1954 else 1955 vlruvp(vp); 1956 splx(s); 1957 } 1958 1959 /* 1960 * Remove any vnodes in the vnode table belonging to mount point mp. 1961 * 1962 * If FORCECLOSE is not specified, there should not be any active ones, 1963 * return error if any are found (nb: this is a user error, not a 1964 * system error). If FORCECLOSE is specified, detach any active vnodes 1965 * that are found. 1966 * 1967 * If WRITECLOSE is set, only flush out regular file vnodes open for 1968 * writing. 1969 * 1970 * SKIPSYSTEM causes any vnodes marked VSYSTEM to be skipped. 1971 * 1972 * `rootrefs' specifies the base reference count for the root vnode 1973 * of this filesystem. The root vnode is considered busy if its 1974 * v_usecount exceeds this value. On a successful return, vflush() 1975 * will call vrele() on the root vnode exactly rootrefs times. 1976 * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must 1977 * be zero. 1978 */ 1979 #ifdef DIAGNOSTIC 1980 static int busyprt = 0; /* print out busy vnodes */ 1981 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, ""); 1982 #endif 1983 1984 int 1985 vflush(mp, rootrefs, flags) 1986 struct mount *mp; 1987 int rootrefs; 1988 int flags; 1989 { 1990 struct thread *td = curthread; /* XXX */ 1991 struct vnode *vp, *nvp, *rootvp = NULL; 1992 struct vattr vattr; 1993 int busy = 0, error; 1994 1995 if (rootrefs > 0) { 1996 KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, 1997 ("vflush: bad args")); 1998 /* 1999 * Get the filesystem root vnode. We can vput() it 2000 * immediately, since with rootrefs > 0, it won't go away. 2001 */ 2002 if ((error = VFS_ROOT(mp, &rootvp)) != 0) 2003 return (error); 2004 vput(rootvp); 2005 2006 } 2007 mtx_lock(&mntvnode_mtx); 2008 loop: 2009 for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp; vp = nvp) { 2010 /* 2011 * Make sure this vnode wasn't reclaimed in getnewvnode(). 2012 * Start over if it has (it won't be on the list anymore). 2013 */ 2014 if (vp->v_mount != mp) 2015 goto loop; 2016 nvp = TAILQ_NEXT(vp, v_nmntvnodes); 2017 2018 mtx_unlock(&mntvnode_mtx); 2019 mtx_lock(&vp->v_interlock); 2020 /* 2021 * Skip over a vnodes marked VSYSTEM. 2022 */ 2023 if ((flags & SKIPSYSTEM) && (vp->v_flag & VSYSTEM)) { 2024 mtx_unlock(&vp->v_interlock); 2025 mtx_lock(&mntvnode_mtx); 2026 continue; 2027 } 2028 /* 2029 * If WRITECLOSE is set, flush out unlinked but still open 2030 * files (even if open only for reading) and regular file 2031 * vnodes open for writing. 2032 */ 2033 if ((flags & WRITECLOSE) && 2034 (vp->v_type == VNON || 2035 (VOP_GETATTR(vp, &vattr, td->td_ucred, td) == 0 && 2036 vattr.va_nlink > 0)) && 2037 (vp->v_writecount == 0 || vp->v_type != VREG)) { 2038 mtx_unlock(&vp->v_interlock); 2039 mtx_lock(&mntvnode_mtx); 2040 continue; 2041 } 2042 2043 /* 2044 * With v_usecount == 0, all we need to do is clear out the 2045 * vnode data structures and we are done. 2046 */ 2047 if (vp->v_usecount == 0) { 2048 vgonel(vp, td); 2049 mtx_lock(&mntvnode_mtx); 2050 continue; 2051 } 2052 2053 /* 2054 * If FORCECLOSE is set, forcibly close the vnode. For block 2055 * or character devices, revert to an anonymous device. For 2056 * all other files, just kill them. 2057 */ 2058 if (flags & FORCECLOSE) { 2059 if (vp->v_type != VCHR) { 2060 vgonel(vp, td); 2061 } else { 2062 vclean(vp, 0, td); 2063 vp->v_op = spec_vnodeop_p; 2064 insmntque(vp, (struct mount *) 0); 2065 } 2066 mtx_lock(&mntvnode_mtx); 2067 continue; 2068 } 2069 #ifdef DIAGNOSTIC 2070 if (busyprt) 2071 vprint("vflush: busy vnode", vp); 2072 #endif 2073 mtx_unlock(&vp->v_interlock); 2074 mtx_lock(&mntvnode_mtx); 2075 busy++; 2076 } 2077 mtx_unlock(&mntvnode_mtx); 2078 if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { 2079 /* 2080 * If just the root vnode is busy, and if its refcount 2081 * is equal to `rootrefs', then go ahead and kill it. 2082 */ 2083 mtx_lock(&rootvp->v_interlock); 2084 KASSERT(busy > 0, ("vflush: not busy")); 2085 KASSERT(rootvp->v_usecount >= rootrefs, ("vflush: rootrefs")); 2086 if (busy == 1 && rootvp->v_usecount == rootrefs) { 2087 vgonel(rootvp, td); 2088 busy = 0; 2089 } else 2090 mtx_unlock(&rootvp->v_interlock); 2091 } 2092 if (busy) 2093 return (EBUSY); 2094 for (; rootrefs > 0; rootrefs--) 2095 vrele(rootvp); 2096 return (0); 2097 } 2098 2099 /* 2100 * This moves a now (likely recyclable) vnode to the end of the 2101 * mountlist. XXX However, it is temporarily disabled until we 2102 * can clean up ffs_sync() and friends, which have loop restart 2103 * conditions which this code causes to operate O(N^2). 2104 */ 2105 static void 2106 vlruvp(struct vnode *vp) 2107 { 2108 #if 0 2109 struct mount *mp; 2110 2111 if ((mp = vp->v_mount) != NULL) { 2112 mtx_lock(&mntvnode_mtx); 2113 TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 2114 TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); 2115 mtx_unlock(&mntvnode_mtx); 2116 } 2117 #endif 2118 } 2119 2120 /* 2121 * Disassociate the underlying filesystem from a vnode. 2122 */ 2123 static void 2124 vclean(vp, flags, td) 2125 struct vnode *vp; 2126 int flags; 2127 struct thread *td; 2128 { 2129 int active; 2130 2131 /* 2132 * Check to see if the vnode is in use. If so we have to reference it 2133 * before we clean it out so that its count cannot fall to zero and 2134 * generate a race against ourselves to recycle it. 2135 */ 2136 if ((active = vp->v_usecount)) 2137 vp->v_usecount++; 2138 2139 /* 2140 * Prevent the vnode from being recycled or brought into use while we 2141 * clean it out. 2142 */ 2143 if (vp->v_flag & VXLOCK) 2144 panic("vclean: deadlock"); 2145 vp->v_flag |= VXLOCK; 2146 vp->v_vxproc = curthread; 2147 /* 2148 * Even if the count is zero, the VOP_INACTIVE routine may still 2149 * have the object locked while it cleans it out. The VOP_LOCK 2150 * ensures that the VOP_INACTIVE routine is done with its work. 2151 * For active vnodes, it ensures that no other activity can 2152 * occur while the underlying object is being cleaned out. 2153 */ 2154 VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, td); 2155 2156 /* 2157 * Clean out any buffers associated with the vnode. 2158 * If the flush fails, just toss the buffers. 2159 */ 2160 if (flags & DOCLOSE) { 2161 if (TAILQ_FIRST(&vp->v_dirtyblkhd) != NULL) 2162 (void) vn_write_suspend_wait(vp, NULL, V_WAIT); 2163 if (vinvalbuf(vp, V_SAVE, NOCRED, td, 0, 0) != 0) 2164 vinvalbuf(vp, 0, NOCRED, td, 0, 0); 2165 } 2166 2167 VOP_DESTROYVOBJECT(vp); 2168 2169 /* 2170 * Any other processes trying to obtain this lock must first 2171 * wait for VXLOCK to clear, then call the new lock operation. 2172 */ 2173 VOP_UNLOCK(vp, 0, td); 2174 2175 /* 2176 * If purging an active vnode, it must be closed and 2177 * deactivated before being reclaimed. Note that the 2178 * VOP_INACTIVE will unlock the vnode. 2179 */ 2180 if (active) { 2181 if (flags & DOCLOSE) 2182 VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); 2183 if (vn_lock(vp, LK_EXCLUSIVE | LK_NOWAIT, td) != 0) 2184 panic("vclean: cannot relock."); 2185 VOP_INACTIVE(vp, td); 2186 } 2187 2188 /* 2189 * Reclaim the vnode. 2190 */ 2191 if (VOP_RECLAIM(vp, td)) 2192 panic("vclean: cannot reclaim"); 2193 2194 if (active) { 2195 /* 2196 * Inline copy of vrele() since VOP_INACTIVE 2197 * has already been called. 2198 */ 2199 mtx_lock(&vp->v_interlock); 2200 if (--vp->v_usecount <= 0) { 2201 #ifdef DIAGNOSTIC 2202 if (vp->v_usecount < 0 || vp->v_writecount != 0) { 2203 vprint("vclean: bad ref count", vp); 2204 panic("vclean: ref cnt"); 2205 } 2206 #endif 2207 vfree(vp); 2208 } 2209 mtx_unlock(&vp->v_interlock); 2210 } 2211 2212 cache_purge(vp); 2213 vp->v_vnlock = NULL; 2214 lockdestroy(&vp->v_lock); 2215 2216 if (VSHOULDFREE(vp)) 2217 vfree(vp); 2218 2219 /* 2220 * Done with purge, notify sleepers of the grim news. 2221 */ 2222 vp->v_op = dead_vnodeop_p; 2223 if (vp->v_pollinfo != NULL) 2224 vn_pollgone(vp); 2225 vp->v_tag = VT_NON; 2226 vp->v_flag &= ~VXLOCK; 2227 vp->v_vxproc = NULL; 2228 if (vp->v_flag & VXWANT) { 2229 vp->v_flag &= ~VXWANT; 2230 wakeup(vp); 2231 } 2232 } 2233 2234 /* 2235 * Eliminate all activity associated with the requested vnode 2236 * and with all vnodes aliased to the requested vnode. 2237 */ 2238 int 2239 vop_revoke(ap) 2240 struct vop_revoke_args /* { 2241 struct vnode *a_vp; 2242 int a_flags; 2243 } */ *ap; 2244 { 2245 struct vnode *vp, *vq; 2246 dev_t dev; 2247 2248 KASSERT((ap->a_flags & REVOKEALL) != 0, ("vop_revoke")); 2249 2250 vp = ap->a_vp; 2251 /* 2252 * If a vgone (or vclean) is already in progress, 2253 * wait until it is done and return. 2254 */ 2255 if (vp->v_flag & VXLOCK) { 2256 vp->v_flag |= VXWANT; 2257 msleep(vp, &vp->v_interlock, PINOD | PDROP, 2258 "vop_revokeall", 0); 2259 return (0); 2260 } 2261 dev = vp->v_rdev; 2262 for (;;) { 2263 mtx_lock(&spechash_mtx); 2264 vq = SLIST_FIRST(&dev->si_hlist); 2265 mtx_unlock(&spechash_mtx); 2266 if (!vq) 2267 break; 2268 vgone(vq); 2269 } 2270 return (0); 2271 } 2272 2273 /* 2274 * Recycle an unused vnode to the front of the free list. 2275 * Release the passed interlock if the vnode will be recycled. 2276 */ 2277 int 2278 vrecycle(vp, inter_lkp, td) 2279 struct vnode *vp; 2280 struct mtx *inter_lkp; 2281 struct thread *td; 2282 { 2283 2284 mtx_lock(&vp->v_interlock); 2285 if (vp->v_usecount == 0) { 2286 if (inter_lkp) { 2287 mtx_unlock(inter_lkp); 2288 } 2289 vgonel(vp, td); 2290 return (1); 2291 } 2292 mtx_unlock(&vp->v_interlock); 2293 return (0); 2294 } 2295 2296 /* 2297 * Eliminate all activity associated with a vnode 2298 * in preparation for reuse. 2299 */ 2300 void 2301 vgone(vp) 2302 register struct vnode *vp; 2303 { 2304 struct thread *td = curthread; /* XXX */ 2305 2306 mtx_lock(&vp->v_interlock); 2307 vgonel(vp, td); 2308 } 2309 2310 /* 2311 * vgone, with the vp interlock held. 2312 */ 2313 void 2314 vgonel(vp, td) 2315 struct vnode *vp; 2316 struct thread *td; 2317 { 2318 int s; 2319 2320 /* 2321 * If a vgone (or vclean) is already in progress, 2322 * wait until it is done and return. 2323 */ 2324 if (vp->v_flag & VXLOCK) { 2325 vp->v_flag |= VXWANT; 2326 msleep(vp, &vp->v_interlock, PINOD | PDROP, "vgone", 0); 2327 return; 2328 } 2329 2330 /* 2331 * Clean out the filesystem specific data. 2332 */ 2333 vclean(vp, DOCLOSE, td); 2334 mtx_lock(&vp->v_interlock); 2335 2336 /* 2337 * Delete from old mount point vnode list, if on one. 2338 */ 2339 if (vp->v_mount != NULL) 2340 insmntque(vp, (struct mount *)0); 2341 /* 2342 * If special device, remove it from special device alias list 2343 * if it is on one. 2344 */ 2345 if (vp->v_type == VCHR && vp->v_rdev != NULL && vp->v_rdev != NODEV) { 2346 mtx_lock(&spechash_mtx); 2347 SLIST_REMOVE(&vp->v_rdev->si_hlist, vp, vnode, v_specnext); 2348 freedev(vp->v_rdev); 2349 mtx_unlock(&spechash_mtx); 2350 vp->v_rdev = NULL; 2351 } 2352 2353 /* 2354 * If it is on the freelist and not already at the head, 2355 * move it to the head of the list. The test of the 2356 * VDOOMED flag and the reference count of zero is because 2357 * it will be removed from the free list by getnewvnode, 2358 * but will not have its reference count incremented until 2359 * after calling vgone. If the reference count were 2360 * incremented first, vgone would (incorrectly) try to 2361 * close the previous instance of the underlying object. 2362 */ 2363 if (vp->v_usecount == 0 && !(vp->v_flag & VDOOMED)) { 2364 s = splbio(); 2365 mtx_lock(&vnode_free_list_mtx); 2366 if (vp->v_flag & VFREE) 2367 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 2368 else 2369 freevnodes++; 2370 vp->v_flag |= VFREE; 2371 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 2372 mtx_unlock(&vnode_free_list_mtx); 2373 splx(s); 2374 } 2375 2376 vp->v_type = VBAD; 2377 mtx_unlock(&vp->v_interlock); 2378 } 2379 2380 /* 2381 * Lookup a vnode by device number. 2382 */ 2383 int 2384 vfinddev(dev, type, vpp) 2385 dev_t dev; 2386 enum vtype type; 2387 struct vnode **vpp; 2388 { 2389 struct vnode *vp; 2390 2391 mtx_lock(&spechash_mtx); 2392 SLIST_FOREACH(vp, &dev->si_hlist, v_specnext) { 2393 if (type == vp->v_type) { 2394 *vpp = vp; 2395 mtx_unlock(&spechash_mtx); 2396 return (1); 2397 } 2398 } 2399 mtx_unlock(&spechash_mtx); 2400 return (0); 2401 } 2402 2403 /* 2404 * Calculate the total number of references to a special device. 2405 */ 2406 int 2407 vcount(vp) 2408 struct vnode *vp; 2409 { 2410 struct vnode *vq; 2411 int count; 2412 2413 count = 0; 2414 mtx_lock(&spechash_mtx); 2415 SLIST_FOREACH(vq, &vp->v_rdev->si_hlist, v_specnext) 2416 count += vq->v_usecount; 2417 mtx_unlock(&spechash_mtx); 2418 return (count); 2419 } 2420 2421 /* 2422 * Same as above, but using the dev_t as argument 2423 */ 2424 int 2425 count_dev(dev) 2426 dev_t dev; 2427 { 2428 struct vnode *vp; 2429 2430 vp = SLIST_FIRST(&dev->si_hlist); 2431 if (vp == NULL) 2432 return (0); 2433 return(vcount(vp)); 2434 } 2435 2436 /* 2437 * Print out a description of a vnode. 2438 */ 2439 static char *typename[] = 2440 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD"}; 2441 2442 void 2443 vprint(label, vp) 2444 char *label; 2445 struct vnode *vp; 2446 { 2447 char buf[96]; 2448 2449 if (label != NULL) 2450 printf("%s: %p: ", label, (void *)vp); 2451 else 2452 printf("%p: ", (void *)vp); 2453 printf("type %s, usecount %d, writecount %d, refcount %d,", 2454 typename[vp->v_type], vp->v_usecount, vp->v_writecount, 2455 vp->v_holdcnt); 2456 buf[0] = '\0'; 2457 if (vp->v_flag & VROOT) 2458 strcat(buf, "|VROOT"); 2459 if (vp->v_flag & VTEXT) 2460 strcat(buf, "|VTEXT"); 2461 if (vp->v_flag & VSYSTEM) 2462 strcat(buf, "|VSYSTEM"); 2463 if (vp->v_flag & VXLOCK) 2464 strcat(buf, "|VXLOCK"); 2465 if (vp->v_flag & VXWANT) 2466 strcat(buf, "|VXWANT"); 2467 if (vp->v_flag & VBWAIT) 2468 strcat(buf, "|VBWAIT"); 2469 if (vp->v_flag & VDOOMED) 2470 strcat(buf, "|VDOOMED"); 2471 if (vp->v_flag & VFREE) 2472 strcat(buf, "|VFREE"); 2473 if (vp->v_flag & VOBJBUF) 2474 strcat(buf, "|VOBJBUF"); 2475 if (buf[0] != '\0') 2476 printf(" flags (%s)", &buf[1]); 2477 if (vp->v_data == NULL) { 2478 printf("\n"); 2479 } else { 2480 printf("\n\t"); 2481 VOP_PRINT(vp); 2482 } 2483 } 2484 2485 #ifdef DDB 2486 #include <ddb/ddb.h> 2487 /* 2488 * List all of the locked vnodes in the system. 2489 * Called when debugging the kernel. 2490 */ 2491 DB_SHOW_COMMAND(lockedvnods, lockedvnodes) 2492 { 2493 struct thread *td = curthread; /* XXX */ 2494 struct mount *mp, *nmp; 2495 struct vnode *vp; 2496 2497 printf("Locked vnodes\n"); 2498 mtx_lock(&mountlist_mtx); 2499 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 2500 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) { 2501 nmp = TAILQ_NEXT(mp, mnt_list); 2502 continue; 2503 } 2504 mtx_lock(&mntvnode_mtx); 2505 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { 2506 if (VOP_ISLOCKED(vp, NULL)) 2507 vprint((char *)0, vp); 2508 } 2509 mtx_unlock(&mntvnode_mtx); 2510 mtx_lock(&mountlist_mtx); 2511 nmp = TAILQ_NEXT(mp, mnt_list); 2512 vfs_unbusy(mp, td); 2513 } 2514 mtx_unlock(&mountlist_mtx); 2515 } 2516 #endif 2517 2518 /* 2519 * Top level filesystem related information gathering. 2520 */ 2521 static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); 2522 2523 static int 2524 vfs_sysctl(SYSCTL_HANDLER_ARGS) 2525 { 2526 int *name = (int *)arg1 - 1; /* XXX */ 2527 u_int namelen = arg2 + 1; /* XXX */ 2528 struct vfsconf *vfsp; 2529 2530 #if 1 || defined(COMPAT_PRELITE2) 2531 /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ 2532 if (namelen == 1) 2533 return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); 2534 #endif 2535 2536 /* XXX the below code does not compile; vfs_sysctl does not exist. */ 2537 #ifdef notyet 2538 /* all sysctl names at this level are at least name and field */ 2539 if (namelen < 2) 2540 return (ENOTDIR); /* overloaded */ 2541 if (name[0] != VFS_GENERIC) { 2542 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) 2543 if (vfsp->vfc_typenum == name[0]) 2544 break; 2545 if (vfsp == NULL) 2546 return (EOPNOTSUPP); 2547 return ((*vfsp->vfc_vfsops->vfs_sysctl)(&name[1], namelen - 1, 2548 oldp, oldlenp, newp, newlen, td)); 2549 } 2550 #endif 2551 switch (name[1]) { 2552 case VFS_MAXTYPENUM: 2553 if (namelen != 2) 2554 return (ENOTDIR); 2555 return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); 2556 case VFS_CONF: 2557 if (namelen != 3) 2558 return (ENOTDIR); /* overloaded */ 2559 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) 2560 if (vfsp->vfc_typenum == name[2]) 2561 break; 2562 if (vfsp == NULL) 2563 return (EOPNOTSUPP); 2564 return (SYSCTL_OUT(req, vfsp, sizeof *vfsp)); 2565 } 2566 return (EOPNOTSUPP); 2567 } 2568 2569 SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD, vfs_sysctl, 2570 "Generic filesystem"); 2571 2572 #if 1 || defined(COMPAT_PRELITE2) 2573 2574 static int 2575 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) 2576 { 2577 int error; 2578 struct vfsconf *vfsp; 2579 struct ovfsconf ovfs; 2580 2581 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) { 2582 ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ 2583 strcpy(ovfs.vfc_name, vfsp->vfc_name); 2584 ovfs.vfc_index = vfsp->vfc_typenum; 2585 ovfs.vfc_refcount = vfsp->vfc_refcount; 2586 ovfs.vfc_flags = vfsp->vfc_flags; 2587 error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); 2588 if (error) 2589 return error; 2590 } 2591 return 0; 2592 } 2593 2594 #endif /* 1 || COMPAT_PRELITE2 */ 2595 2596 #if COMPILING_LINT 2597 #define KINFO_VNODESLOP 10 2598 /* 2599 * Dump vnode list (via sysctl). 2600 * Copyout address of vnode followed by vnode. 2601 */ 2602 /* ARGSUSED */ 2603 static int 2604 sysctl_vnode(SYSCTL_HANDLER_ARGS) 2605 { 2606 struct thread *td = curthread; /* XXX */ 2607 struct mount *mp, *nmp; 2608 struct vnode *nvp, *vp; 2609 int error; 2610 2611 #define VPTRSZ sizeof (struct vnode *) 2612 #define VNODESZ sizeof (struct vnode) 2613 2614 req->lock = 0; 2615 if (!req->oldptr) /* Make an estimate */ 2616 return (SYSCTL_OUT(req, 0, 2617 (numvnodes + KINFO_VNODESLOP) * (VPTRSZ + VNODESZ))); 2618 2619 mtx_lock(&mountlist_mtx); 2620 for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { 2621 if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) { 2622 nmp = TAILQ_NEXT(mp, mnt_list); 2623 continue; 2624 } 2625 mtx_lock(&mntvnode_mtx); 2626 again: 2627 for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 2628 vp != NULL; 2629 vp = nvp) { 2630 /* 2631 * Check that the vp is still associated with 2632 * this filesystem. RACE: could have been 2633 * recycled onto the same filesystem. 2634 */ 2635 if (vp->v_mount != mp) 2636 goto again; 2637 nvp = TAILQ_NEXT(vp, v_nmntvnodes); 2638 mtx_unlock(&mntvnode_mtx); 2639 if ((error = SYSCTL_OUT(req, &vp, VPTRSZ)) || 2640 (error = SYSCTL_OUT(req, vp, VNODESZ))) 2641 return (error); 2642 mtx_lock(&mntvnode_mtx); 2643 } 2644 mtx_unlock(&mntvnode_mtx); 2645 mtx_lock(&mountlist_mtx); 2646 nmp = TAILQ_NEXT(mp, mnt_list); 2647 vfs_unbusy(mp, td); 2648 } 2649 mtx_unlock(&mountlist_mtx); 2650 2651 return (0); 2652 } 2653 2654 /* 2655 * XXX 2656 * Exporting the vnode list on large systems causes them to crash. 2657 * Exporting the vnode list on medium systems causes sysctl to coredump. 2658 */ 2659 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD, 2660 0, 0, sysctl_vnode, "S,vnode", ""); 2661 #endif 2662 2663 /* 2664 * Check to see if a filesystem is mounted on a block device. 2665 */ 2666 int 2667 vfs_mountedon(vp) 2668 struct vnode *vp; 2669 { 2670 2671 if (vp->v_rdev->si_mountpoint != NULL) 2672 return (EBUSY); 2673 return (0); 2674 } 2675 2676 /* 2677 * Unmount all filesystems. The list is traversed in reverse order 2678 * of mounting to avoid dependencies. 2679 */ 2680 void 2681 vfs_unmountall() 2682 { 2683 struct mount *mp; 2684 struct thread *td; 2685 int error; 2686 2687 if (curthread != NULL) 2688 td = curthread; 2689 else 2690 td = FIRST_THREAD_IN_PROC(initproc); /* XXX XXX proc0? */ 2691 /* 2692 * Since this only runs when rebooting, it is not interlocked. 2693 */ 2694 while(!TAILQ_EMPTY(&mountlist)) { 2695 mp = TAILQ_LAST(&mountlist, mntlist); 2696 error = dounmount(mp, MNT_FORCE, td); 2697 if (error) { 2698 TAILQ_REMOVE(&mountlist, mp, mnt_list); 2699 printf("unmount of %s failed (", 2700 mp->mnt_stat.f_mntonname); 2701 if (error == EBUSY) 2702 printf("BUSY)\n"); 2703 else 2704 printf("%d)\n", error); 2705 } else { 2706 /* The unmount has removed mp from the mountlist */ 2707 } 2708 } 2709 } 2710 2711 /* 2712 * perform msync on all vnodes under a mount point 2713 * the mount point must be locked. 2714 */ 2715 void 2716 vfs_msync(struct mount *mp, int flags) 2717 { 2718 struct vnode *vp, *nvp; 2719 struct vm_object *obj; 2720 int tries; 2721 2722 GIANT_REQUIRED; 2723 2724 tries = 5; 2725 mtx_lock(&mntvnode_mtx); 2726 loop: 2727 for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nvp) { 2728 if (vp->v_mount != mp) { 2729 if (--tries > 0) 2730 goto loop; 2731 break; 2732 } 2733 nvp = TAILQ_NEXT(vp, v_nmntvnodes); 2734 2735 if (vp->v_flag & VXLOCK) /* XXX: what if MNT_WAIT? */ 2736 continue; 2737 2738 if (vp->v_flag & VNOSYNC) /* unlinked, skip it */ 2739 continue; 2740 2741 if ((vp->v_flag & VOBJDIRTY) && 2742 (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) { 2743 mtx_unlock(&mntvnode_mtx); 2744 if (!vget(vp, 2745 LK_EXCLUSIVE | LK_RETRY | LK_NOOBJ, curthread)) { 2746 if (VOP_GETVOBJECT(vp, &obj) == 0) { 2747 vm_object_page_clean(obj, 0, 0, 2748 flags == MNT_WAIT ? 2749 OBJPC_SYNC : OBJPC_NOSYNC); 2750 } 2751 vput(vp); 2752 } 2753 mtx_lock(&mntvnode_mtx); 2754 if (TAILQ_NEXT(vp, v_nmntvnodes) != nvp) { 2755 if (--tries > 0) 2756 goto loop; 2757 break; 2758 } 2759 } 2760 } 2761 mtx_unlock(&mntvnode_mtx); 2762 } 2763 2764 /* 2765 * Create the VM object needed for VMIO and mmap support. This 2766 * is done for all VREG files in the system. Some filesystems might 2767 * afford the additional metadata buffering capability of the 2768 * VMIO code by making the device node be VMIO mode also. 2769 * 2770 * vp must be locked when vfs_object_create is called. 2771 */ 2772 int 2773 vfs_object_create(vp, td, cred) 2774 struct vnode *vp; 2775 struct thread *td; 2776 struct ucred *cred; 2777 { 2778 GIANT_REQUIRED; 2779 return (VOP_CREATEVOBJECT(vp, cred, td)); 2780 } 2781 2782 /* 2783 * Mark a vnode as free, putting it up for recycling. 2784 */ 2785 void 2786 vfree(vp) 2787 struct vnode *vp; 2788 { 2789 int s; 2790 2791 s = splbio(); 2792 mtx_lock(&vnode_free_list_mtx); 2793 KASSERT((vp->v_flag & VFREE) == 0, ("vnode already free")); 2794 if (vp->v_flag & VAGE) { 2795 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 2796 } else { 2797 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 2798 } 2799 freevnodes++; 2800 mtx_unlock(&vnode_free_list_mtx); 2801 vp->v_flag &= ~VAGE; 2802 vp->v_flag |= VFREE; 2803 splx(s); 2804 } 2805 2806 /* 2807 * Opposite of vfree() - mark a vnode as in use. 2808 */ 2809 void 2810 vbusy(vp) 2811 struct vnode *vp; 2812 { 2813 int s; 2814 2815 s = splbio(); 2816 mtx_lock(&vnode_free_list_mtx); 2817 KASSERT((vp->v_flag & VFREE) != 0, ("vnode not free")); 2818 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 2819 freevnodes--; 2820 mtx_unlock(&vnode_free_list_mtx); 2821 vp->v_flag &= ~(VFREE|VAGE); 2822 splx(s); 2823 } 2824 2825 /* 2826 * Record a process's interest in events which might happen to 2827 * a vnode. Because poll uses the historic select-style interface 2828 * internally, this routine serves as both the ``check for any 2829 * pending events'' and the ``record my interest in future events'' 2830 * functions. (These are done together, while the lock is held, 2831 * to avoid race conditions.) 2832 */ 2833 int 2834 vn_pollrecord(vp, td, events) 2835 struct vnode *vp; 2836 struct thread *td; 2837 short events; 2838 { 2839 2840 if (vp->v_pollinfo == NULL) 2841 v_addpollinfo(vp); 2842 mtx_lock(&vp->v_pollinfo->vpi_lock); 2843 if (vp->v_pollinfo->vpi_revents & events) { 2844 /* 2845 * This leaves events we are not interested 2846 * in available for the other process which 2847 * which presumably had requested them 2848 * (otherwise they would never have been 2849 * recorded). 2850 */ 2851 events &= vp->v_pollinfo->vpi_revents; 2852 vp->v_pollinfo->vpi_revents &= ~events; 2853 2854 mtx_unlock(&vp->v_pollinfo->vpi_lock); 2855 return events; 2856 } 2857 vp->v_pollinfo->vpi_events |= events; 2858 selrecord(td, &vp->v_pollinfo->vpi_selinfo); 2859 mtx_unlock(&vp->v_pollinfo->vpi_lock); 2860 return 0; 2861 } 2862 2863 /* 2864 * Note the occurrence of an event. If the VN_POLLEVENT macro is used, 2865 * it is possible for us to miss an event due to race conditions, but 2866 * that condition is expected to be rare, so for the moment it is the 2867 * preferred interface. 2868 */ 2869 void 2870 vn_pollevent(vp, events) 2871 struct vnode *vp; 2872 short events; 2873 { 2874 2875 if (vp->v_pollinfo == NULL) 2876 v_addpollinfo(vp); 2877 mtx_lock(&vp->v_pollinfo->vpi_lock); 2878 if (vp->v_pollinfo->vpi_events & events) { 2879 /* 2880 * We clear vpi_events so that we don't 2881 * call selwakeup() twice if two events are 2882 * posted before the polling process(es) is 2883 * awakened. This also ensures that we take at 2884 * most one selwakeup() if the polling process 2885 * is no longer interested. However, it does 2886 * mean that only one event can be noticed at 2887 * a time. (Perhaps we should only clear those 2888 * event bits which we note?) XXX 2889 */ 2890 vp->v_pollinfo->vpi_events = 0; /* &= ~events ??? */ 2891 vp->v_pollinfo->vpi_revents |= events; 2892 selwakeup(&vp->v_pollinfo->vpi_selinfo); 2893 } 2894 mtx_unlock(&vp->v_pollinfo->vpi_lock); 2895 } 2896 2897 /* 2898 * Wake up anyone polling on vp because it is being revoked. 2899 * This depends on dead_poll() returning POLLHUP for correct 2900 * behavior. 2901 */ 2902 void 2903 vn_pollgone(vp) 2904 struct vnode *vp; 2905 { 2906 2907 mtx_lock(&vp->v_pollinfo->vpi_lock); 2908 VN_KNOTE(vp, NOTE_REVOKE); 2909 if (vp->v_pollinfo->vpi_events) { 2910 vp->v_pollinfo->vpi_events = 0; 2911 selwakeup(&vp->v_pollinfo->vpi_selinfo); 2912 } 2913 mtx_unlock(&vp->v_pollinfo->vpi_lock); 2914 } 2915 2916 2917 2918 /* 2919 * Routine to create and manage a filesystem syncer vnode. 2920 */ 2921 #define sync_close ((int (*)(struct vop_close_args *))nullop) 2922 static int sync_fsync(struct vop_fsync_args *); 2923 static int sync_inactive(struct vop_inactive_args *); 2924 static int sync_reclaim(struct vop_reclaim_args *); 2925 static int sync_print(struct vop_print_args *); 2926 2927 static vop_t **sync_vnodeop_p; 2928 static struct vnodeopv_entry_desc sync_vnodeop_entries[] = { 2929 { &vop_default_desc, (vop_t *) vop_eopnotsupp }, 2930 { &vop_close_desc, (vop_t *) sync_close }, /* close */ 2931 { &vop_fsync_desc, (vop_t *) sync_fsync }, /* fsync */ 2932 { &vop_inactive_desc, (vop_t *) sync_inactive }, /* inactive */ 2933 { &vop_reclaim_desc, (vop_t *) sync_reclaim }, /* reclaim */ 2934 { &vop_lock_desc, (vop_t *) vop_stdlock }, /* lock */ 2935 { &vop_unlock_desc, (vop_t *) vop_stdunlock }, /* unlock */ 2936 { &vop_print_desc, (vop_t *) sync_print }, /* print */ 2937 { &vop_islocked_desc, (vop_t *) vop_stdislocked }, /* islocked */ 2938 { NULL, NULL } 2939 }; 2940 static struct vnodeopv_desc sync_vnodeop_opv_desc = 2941 { &sync_vnodeop_p, sync_vnodeop_entries }; 2942 2943 VNODEOP_SET(sync_vnodeop_opv_desc); 2944 2945 /* 2946 * Create a new filesystem syncer vnode for the specified mount point. 2947 */ 2948 int 2949 vfs_allocate_syncvnode(mp) 2950 struct mount *mp; 2951 { 2952 struct vnode *vp; 2953 static long start, incr, next; 2954 int error; 2955 2956 /* Allocate a new vnode */ 2957 if ((error = getnewvnode(VT_VFS, mp, sync_vnodeop_p, &vp)) != 0) { 2958 mp->mnt_syncer = NULL; 2959 return (error); 2960 } 2961 vp->v_type = VNON; 2962 /* 2963 * Place the vnode onto the syncer worklist. We attempt to 2964 * scatter them about on the list so that they will go off 2965 * at evenly distributed times even if all the filesystems 2966 * are mounted at once. 2967 */ 2968 next += incr; 2969 if (next == 0 || next > syncer_maxdelay) { 2970 start /= 2; 2971 incr /= 2; 2972 if (start == 0) { 2973 start = syncer_maxdelay / 2; 2974 incr = syncer_maxdelay; 2975 } 2976 next = start; 2977 } 2978 vn_syncer_add_to_worklist(vp, syncdelay > 0 ? next % syncdelay : 0); 2979 mp->mnt_syncer = vp; 2980 return (0); 2981 } 2982 2983 /* 2984 * Do a lazy sync of the filesystem. 2985 */ 2986 static int 2987 sync_fsync(ap) 2988 struct vop_fsync_args /* { 2989 struct vnode *a_vp; 2990 struct ucred *a_cred; 2991 int a_waitfor; 2992 struct thread *a_td; 2993 } */ *ap; 2994 { 2995 struct vnode *syncvp = ap->a_vp; 2996 struct mount *mp = syncvp->v_mount; 2997 struct thread *td = ap->a_td; 2998 int asyncflag; 2999 3000 /* 3001 * We only need to do something if this is a lazy evaluation. 3002 */ 3003 if (ap->a_waitfor != MNT_LAZY) 3004 return (0); 3005 3006 /* 3007 * Move ourselves to the back of the sync list. 3008 */ 3009 vn_syncer_add_to_worklist(syncvp, syncdelay); 3010 3011 /* 3012 * Walk the list of vnodes pushing all that are dirty and 3013 * not already on the sync list. 3014 */ 3015 mtx_lock(&mountlist_mtx); 3016 if (vfs_busy(mp, LK_EXCLUSIVE | LK_NOWAIT, &mountlist_mtx, td) != 0) { 3017 mtx_unlock(&mountlist_mtx); 3018 return (0); 3019 } 3020 if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { 3021 vfs_unbusy(mp, td); 3022 return (0); 3023 } 3024 asyncflag = mp->mnt_flag & MNT_ASYNC; 3025 mp->mnt_flag &= ~MNT_ASYNC; 3026 vfs_msync(mp, MNT_NOWAIT); 3027 VFS_SYNC(mp, MNT_LAZY, ap->a_cred, td); 3028 if (asyncflag) 3029 mp->mnt_flag |= MNT_ASYNC; 3030 vn_finished_write(mp); 3031 vfs_unbusy(mp, td); 3032 return (0); 3033 } 3034 3035 /* 3036 * The syncer vnode is no referenced. 3037 */ 3038 static int 3039 sync_inactive(ap) 3040 struct vop_inactive_args /* { 3041 struct vnode *a_vp; 3042 struct thread *a_td; 3043 } */ *ap; 3044 { 3045 3046 vgone(ap->a_vp); 3047 return (0); 3048 } 3049 3050 /* 3051 * The syncer vnode is no longer needed and is being decommissioned. 3052 * 3053 * Modifications to the worklist must be protected at splbio(). 3054 */ 3055 static int 3056 sync_reclaim(ap) 3057 struct vop_reclaim_args /* { 3058 struct vnode *a_vp; 3059 } */ *ap; 3060 { 3061 struct vnode *vp = ap->a_vp; 3062 int s; 3063 3064 s = splbio(); 3065 vp->v_mount->mnt_syncer = NULL; 3066 if (vp->v_flag & VONWORKLST) { 3067 LIST_REMOVE(vp, v_synclist); 3068 vp->v_flag &= ~VONWORKLST; 3069 } 3070 splx(s); 3071 3072 return (0); 3073 } 3074 3075 /* 3076 * Print out a syncer vnode. 3077 */ 3078 static int 3079 sync_print(ap) 3080 struct vop_print_args /* { 3081 struct vnode *a_vp; 3082 } */ *ap; 3083 { 3084 struct vnode *vp = ap->a_vp; 3085 3086 printf("syncer vnode"); 3087 if (vp->v_vnlock != NULL) 3088 lockmgr_printinfo(vp->v_vnlock); 3089 printf("\n"); 3090 return (0); 3091 } 3092 3093 /* 3094 * extract the dev_t from a VCHR 3095 */ 3096 dev_t 3097 vn_todev(vp) 3098 struct vnode *vp; 3099 { 3100 if (vp->v_type != VCHR) 3101 return (NODEV); 3102 return (vp->v_rdev); 3103 } 3104 3105 /* 3106 * Check if vnode represents a disk device 3107 */ 3108 int 3109 vn_isdisk(vp, errp) 3110 struct vnode *vp; 3111 int *errp; 3112 { 3113 struct cdevsw *cdevsw; 3114 3115 if (vp->v_type != VCHR) { 3116 if (errp != NULL) 3117 *errp = ENOTBLK; 3118 return (0); 3119 } 3120 if (vp->v_rdev == NULL) { 3121 if (errp != NULL) 3122 *errp = ENXIO; 3123 return (0); 3124 } 3125 cdevsw = devsw(vp->v_rdev); 3126 if (cdevsw == NULL) { 3127 if (errp != NULL) 3128 *errp = ENXIO; 3129 return (0); 3130 } 3131 if (!(cdevsw->d_flags & D_DISK)) { 3132 if (errp != NULL) 3133 *errp = ENOTBLK; 3134 return (0); 3135 } 3136 if (errp != NULL) 3137 *errp = 0; 3138 return (1); 3139 } 3140 3141 /* 3142 * Free data allocated by namei(); see namei(9) for details. 3143 */ 3144 void 3145 NDFREE(ndp, flags) 3146 struct nameidata *ndp; 3147 const uint flags; 3148 { 3149 if (!(flags & NDF_NO_FREE_PNBUF) && 3150 (ndp->ni_cnd.cn_flags & HASBUF)) { 3151 uma_zfree(namei_zone, ndp->ni_cnd.cn_pnbuf); 3152 ndp->ni_cnd.cn_flags &= ~HASBUF; 3153 } 3154 if (!(flags & NDF_NO_DVP_UNLOCK) && 3155 (ndp->ni_cnd.cn_flags & LOCKPARENT) && 3156 ndp->ni_dvp != ndp->ni_vp) 3157 VOP_UNLOCK(ndp->ni_dvp, 0, ndp->ni_cnd.cn_thread); 3158 if (!(flags & NDF_NO_DVP_RELE) && 3159 (ndp->ni_cnd.cn_flags & (LOCKPARENT|WANTPARENT))) { 3160 vrele(ndp->ni_dvp); 3161 ndp->ni_dvp = NULL; 3162 } 3163 if (!(flags & NDF_NO_VP_UNLOCK) && 3164 (ndp->ni_cnd.cn_flags & LOCKLEAF) && ndp->ni_vp) 3165 VOP_UNLOCK(ndp->ni_vp, 0, ndp->ni_cnd.cn_thread); 3166 if (!(flags & NDF_NO_VP_RELE) && 3167 ndp->ni_vp) { 3168 vrele(ndp->ni_vp); 3169 ndp->ni_vp = NULL; 3170 } 3171 if (!(flags & NDF_NO_STARTDIR_RELE) && 3172 (ndp->ni_cnd.cn_flags & SAVESTART)) { 3173 vrele(ndp->ni_startdir); 3174 ndp->ni_startdir = NULL; 3175 } 3176 } 3177 3178 /* 3179 * Common filesystem object access control check routine. Accepts a 3180 * vnode's type, "mode", uid and gid, requested access mode, credentials, 3181 * and optional call-by-reference privused argument allowing vaccess() 3182 * to indicate to the caller whether privilege was used to satisfy the 3183 * request. Returns 0 on success, or an errno on failure. 3184 */ 3185 int 3186 vaccess(type, file_mode, file_uid, file_gid, acc_mode, cred, privused) 3187 enum vtype type; 3188 mode_t file_mode; 3189 uid_t file_uid; 3190 gid_t file_gid; 3191 mode_t acc_mode; 3192 struct ucred *cred; 3193 int *privused; 3194 { 3195 mode_t dac_granted; 3196 #ifdef CAPABILITIES 3197 mode_t cap_granted; 3198 #endif 3199 3200 /* 3201 * Look for a normal, non-privileged way to access the file/directory 3202 * as requested. If it exists, go with that. 3203 */ 3204 3205 if (privused != NULL) 3206 *privused = 0; 3207 3208 dac_granted = 0; 3209 3210 /* Check the owner. */ 3211 if (cred->cr_uid == file_uid) { 3212 dac_granted |= VADMIN; 3213 if (file_mode & S_IXUSR) 3214 dac_granted |= VEXEC; 3215 if (file_mode & S_IRUSR) 3216 dac_granted |= VREAD; 3217 if (file_mode & S_IWUSR) 3218 dac_granted |= VWRITE; 3219 3220 if ((acc_mode & dac_granted) == acc_mode) 3221 return (0); 3222 3223 goto privcheck; 3224 } 3225 3226 /* Otherwise, check the groups (first match) */ 3227 if (groupmember(file_gid, cred)) { 3228 if (file_mode & S_IXGRP) 3229 dac_granted |= VEXEC; 3230 if (file_mode & S_IRGRP) 3231 dac_granted |= VREAD; 3232 if (file_mode & S_IWGRP) 3233 dac_granted |= VWRITE; 3234 3235 if ((acc_mode & dac_granted) == acc_mode) 3236 return (0); 3237 3238 goto privcheck; 3239 } 3240 3241 /* Otherwise, check everyone else. */ 3242 if (file_mode & S_IXOTH) 3243 dac_granted |= VEXEC; 3244 if (file_mode & S_IROTH) 3245 dac_granted |= VREAD; 3246 if (file_mode & S_IWOTH) 3247 dac_granted |= VWRITE; 3248 if ((acc_mode & dac_granted) == acc_mode) 3249 return (0); 3250 3251 privcheck: 3252 if (!suser_cred(cred, PRISON_ROOT)) { 3253 /* XXX audit: privilege used */ 3254 if (privused != NULL) 3255 *privused = 1; 3256 return (0); 3257 } 3258 3259 #ifdef CAPABILITIES 3260 /* 3261 * Build a capability mask to determine if the set of capabilities 3262 * satisfies the requirements when combined with the granted mask 3263 * from above. 3264 * For each capability, if the capability is required, bitwise 3265 * or the request type onto the cap_granted mask. 3266 */ 3267 cap_granted = 0; 3268 3269 if (type == VDIR) { 3270 /* 3271 * For directories, use CAP_DAC_READ_SEARCH to satisfy 3272 * VEXEC requests, instead of CAP_DAC_EXECUTE. 3273 */ 3274 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3275 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, PRISON_ROOT)) 3276 cap_granted |= VEXEC; 3277 } else { 3278 if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && 3279 !cap_check(cred, NULL, CAP_DAC_EXECUTE, PRISON_ROOT)) 3280 cap_granted |= VEXEC; 3281 } 3282 3283 if ((acc_mode & VREAD) && ((dac_granted & VREAD) == 0) && 3284 !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, PRISON_ROOT)) 3285 cap_granted |= VREAD; 3286 3287 if ((acc_mode & VWRITE) && ((dac_granted & VWRITE) == 0) && 3288 !cap_check(cred, NULL, CAP_DAC_WRITE, PRISON_ROOT)) 3289 cap_granted |= VWRITE; 3290 3291 if ((acc_mode & VADMIN) && ((dac_granted & VADMIN) == 0) && 3292 !cap_check(cred, NULL, CAP_FOWNER, PRISON_ROOT)) 3293 cap_granted |= VADMIN; 3294 3295 if ((acc_mode & (cap_granted | dac_granted)) == acc_mode) { 3296 /* XXX audit: privilege used */ 3297 if (privused != NULL) 3298 *privused = 1; 3299 return (0); 3300 } 3301 #endif 3302 3303 return ((acc_mode & VADMIN) ? EPERM : EACCES); 3304 } 3305